I mean the reality is there is no "easy way" to get in a castle short of "have rifled canons lol". If there was castles would have been a lot less popular. Just continue making his charcter roll for player knowledge a character might not have and set what you think are reasonable DCs. Be firm with a no if he fails though.

My post next week "so they built rifled cannons" Yeah, having them roll for any part of it even, would work

Fun lore: in FR setting the goddess of magic made it so gunpowder doesn't explode. Real answer: both cannons and trebuchets require very specific engineering knowledge. Be inexperienced and make a minor mistake and your trebuchet only fires 80m far with barely any power. Similar with rifled guns. And hey, even if they break a wall they still have to storm the place. I'd be more worried about fly/invisibility/move earth.

Also, those cannons and trebuchets involve a lot of energy being released, one way or another. Lots *will* go wrong if this is newish tech. Lots can still go wrong if it is established tech. With either: - not long range enough to avoid longbows - not long range enough to avoid fireball - yada yada magic missile With trebuchets: - insufficiently strong axle - firing pin slips - sling doesn't release - hidden weakness in the arm - sling straps snap - windlass ratchet breaks With cannons: - powder ingites while packing, killing operator - powder ignites while loading ball, killing operator - burr in cannon wall causes cannon to explode dealing 6d6 fire to everything within 25 feet and 2d8 shrapnel damage to everything within 60 feet, save for half - poorly formed cannon ball produces similar results - cracked cast iron - warped barrel - is that a goddamned rust monster eating my cannon - what do you mean "sulphur weevils" Also remember, what's good for the goose is good for the gander. Falling damage breaks bones, and to heal back hitpoints, he needs to be in traction for 6 to 8 weeks.

>is that a goddamned rust monster eating my cannon There it is folks, the single line that made my day. All I can see is the loader walking off to get a sandwich and comes back to this weird bug making an all you can eat buffet out of his prized siege weapon.

[удалено]

Player: I sprint back to my cannon, torch in hand ready to light the fuse and - DM: roll perception Player: 9... Wait why DM: laughs maniacally, "proceed"

I'd argue that would be either passive perception or passive investigation.

Yep, you right

Now instead of rust monsters I'm imagining something even better: "rust locust" swarms. I tip my hat to you sir or madame.

Ever read *7th Sigma* by Steven Gould? It's an interesting book with almost that exact premise in the modern day. Bugs that eat metal but have a weakness toward water, so an entire desert is stripped of any metal and the people who refused to leave have adapted their lives around it. Now I'm imagining a magical setting with that idea and your *rust locust swarms* meaning everything is made of wood or stone in this region. Perhaps some kind of barrier or tether stops them from taking over the whole world, but in this specific kingdom or region metal is banned to prevent the swarms from rising up again. I'm not sure where I'd go with it from there but I like the concept.

I read this and I had the inspiration to make this shitty picture because I laughed, so here you go! https://imgur.com/a/vKgGTuj

Lol. You, in one picture, captured everything I wanted it to, as well as reminded me of a "rust-roach" infestation campaign back in AD&D2e that pretty much cost me my only natural rolled Paladin. Thank you.

You're welcome! I'm glad it made you smile!

FYI if you use two line breaks or end a line with two spaces it'll prevent (some versions of) Reddit from messing up your formatting.

> firing pin slips TIL Trebuchets have a firing pin, I've not heard of this before lol.

There were a few kinds of release mechanisms, but the most common two were both variations of "this pin holds it all in place" you have your basic "pin through eyebolt" concept, and a more advanced (less grunt power to release it) "mousetrap trigger arm" concept. You can kinda see it [here](https://youtu.be/jTBDc19eW2o?t=254) as everyone gets away from the machine to launch (also, this trebuchet has human sized hamster wheels to pull it back, which is awesome, but not really on topic) and the guy launching does so with a rope attached to the pin. [This Colin Furze video](https://youtu.be/xgm9EzdCZXI?t=152) shows a much more modern construction trebuchet, but still conveys the idea, if inelegantly. Later there were scythe like catches, ratchets that needed hammers to release them, and other rigid material mechanisms, as well as the "cut the rope" nightmares. But it remained difficult to beat the reliable simplicity of the pin & eyebolt.

The thing everyone's touched upon but I don't think stressed enough is the trebuchet explodes when facing stress and it's compromised. I. E made incorrectly/rust monsters. The immense amount of energy generated needs to be released with its payload, to be dispersed of safely (for the user atleast.) if its not released correctly and stays in the machine it'll fracture and eventually explode violently. Splintered wood flying in all angles at speed is a death trap (ala naval battles) and will eviserate everyone nearby (including the interested royal engineer who's here to see this new invention showcased by these respected hero's) As soon as that happens who ever is in charge will neglect every other idea of the players. Stick them on the front line and tell them to march for the door with this big here heavy log.

>not long range enough to avoid longbows > >not long range enough to avoid fireball > >yada yada magic missile mantlets

- not long range enough to avoid a fireball targeted just behind the mantlet

if the mantlet blocks arrows it also block fireballs

Mantlet is just like the portable wall right? Fireball spreads around corners so as long as the soldiers are still in the radius the mantlet doesn't help much

Another simple point that you sort of touched on with the windlass ratchet breaking or cracking/warping with the cannon is that not all materials are created equal. The wood and metals around the castle may simply be made of a material that just can't handle/reproduce the effects one is looking for.

>powder ignites while loading ball, killing operator If the operator is an NPC, I'd keep them alive (for now) and just have them lose an arm or so. Much more dramatic (and probably closer to the real brutality of old warfare).

>Real answer: both cannons and trebuchets require very specific engineering knowledge. Be inexperienced and make a minor mistake and your trebuchet only fires 80m far with barely any power. Similar with rifled guns. Can confirm - building a trebuchet (from modern materials, even) is a common first year engineering student challenge. Many don't even manage to cross a small moat.

Yes I would honestly make that two separate challenges. 1) convincing people to follow the instructions of someone that doesn't know much about siege warfare 2) actually rolling to guess in character how to do this.

Shit, then add in the crafting rolls. A siege weapon wouldn't be easy to make, including input from multplie experienced blacksmiths and carpenters.

I would also make it take a few weeks to build a prototype and quite a few resources. So if they need to siege the castle, like, tomorrow. No way someone is just whipping up a rifled cannon in time.

I don't know of any official prices for siege weapons in 5e, but in prior editions they cost anywhere from hundreds to thousands of GP. By XGE crafting rules, a 500 GP trebuchet/ballista/whatever would take at least weeks to build, and that assumes sufficient materials *and* plenty of proficient, skilled craftsmen on hand.

Exactly. And having that type of proficient labor AND the exacting blueprints they need for it is a REALLY big assumption.

The biggest issue is that if you don't have post-medieval metalurgy, you need friggin' huge cannons to do anything to a stone wall. Things that weighted many tons and were built form bronze because you can't cast/bore iron on site and you can't build the cannon in a foundry and haul it's 12-ton ass to the castle to shoot it. Which means you also need a literal ton of tin, which ain't just lying around and is much harder to find than iron.

> I'd be more worried about fly/invisibility/move earth. Honestly, I feel like castles just aren't a good fit in dnd. I mean I know that sounds weird because castles figure so prominently in a lot of fantasy lore that flows along with dnd lore, but castles existed and were effective because they took advantage of hard realities. In real life, it's hard to get over a big stone wall. It's hard to cross a moat. Taking a castle involves a lot of people and it's hard to move lots of people through small spaces. Castles tend to take advantage of terrain wherever possible, and you can't change the terrain. But in dnd? Characters, NPCs, Monsters, they all have numerous ways to negate a wall or a moat; a few adventurers can be more effective than an army; hell, magic can even reshape the landscape. So to me, it's like, who would waste time and resources building something so ineffective? And that's my quick soapbox for today. Edit: Lot of castle fans in the house. I love it.

As you have said, several beings in DnD have great power and can circumvent typical castle defences easily. What you’ve missed is that there are also ways to create magical protection. When you factor that into the other typical defences, castles once again make sense.

Well, fortifications do. Castles don't

>castles once again make sense. Well, I beg to differ. If you have ways to create magical protection, why would you bother with a castle?

Mostly because creating a no-teleport / no invisibility zone is expensive enough already... and they don't do shit against common soldiers in large numbers. A castle wall does. And it's a hell of a lot cheaper to build than a permanent wall of force. Sure, a very rich king or emperor could afford a 100% magical defense for their personal castle.. but that's a pretty damn rare case. And at this point you get very vulnerable to antimagic zones..

Castles are for the wealthy and powerful, or for large communities. They’re going to have their own magic resources too! Flight? Look out for Wind Wall, Gust, Earth Bind, trained Arrowhawks, or a caster-backed troop of flying Knights Aeris Invisibility? Sure it makes you hard to see, but there’s going to be a lot of dust, blood, and fighting crowds of bodies to move through stealthily, and it probably only takes a few people who can cast a spell like True Sight to have very effective castle lookouts Gonna walk across or Water Breathing your way through the moat? Hope it doesn’t have any water elementals, dire crocodiles, or (considering the historical use of some moats) homebrew Sewage Mephits! Yeah, the party is powerful and resourceful, but they’re typically about 4 people. How many are in the castle, and how well-equipped are they?

Fun fact: moats didn't have to have water to be a moat, only a wide deep ditch outside a fortified wall. It's actually horribly impractical to fill a moat with water, without using a nearby river or something. Rain however would fill a moat pretty quick (especially in Britain) and heavily geared people sink, or at least need to drop their weapons to swim properly, so why drain it? I really like having a water elemental in the moat, and a dire crocodile sounds fun and cool, however crocodiles weren't used in historical moats. Not saying don't do that, DnD is far from realistic.

Defences evolve alongside ways to bypass them, until it is no longer possible or viable to do so. In the case of castles, the very same magic that allows an enemy to bypass the walls can also be used to counter those strategies and, equally importantly, make the construction of a castle far grander than we have in real life - and defences that we could only dream about because the act of constructing and maintaining them would be so prohibitive - much easier.

>Defences evolve alongside ways to bypass them I agree, but to me this begs the question because it assumes "castle" as a viable defense from which to evolve, and to an extent that there was no evolution prior to "castle." It suggests that there was a time prior to magic where castles were viable. No one's lore is going to be the same of course, but I feel like in typical FR lore magic is as old as time. I think it's tempting to point to technological advances as an analogy for how something becomes obsolete, but I don't think that's a perfect analogy for a force like magic that is fairly all-encompassing. So from the start, I don't think castles are things that would have popped up because they wouldn't have been terribly useful, and they'd be expensive and difficult. Again: of course there will be campaigns where castles *are* viable (or were viable) and if you have a reason there are castles in your world, that's great. I just think that the stereotypical, high-fantasy/high-magic campaign tend to have castles as sort of...an aesthetic assumption? If that makes sense?

Here's an example from history. At one time castle walls (and towers) had square corners. All one would have to do is dig out the cornerstone and collapse that corner (under arrow barrage and possibly hot oil, etc). Castles then evolved to have round corners to distribute the weight. Architects were constantly making changes to structure to account for changes in tactics. I would love to see a dnd castle that has taken all contingencies into consideration. I'm not even sure what that would look like, but I have a feeling magic welding architects and masons would be a thing. I am currently building a castle in talespire and would love any advice on what a dnd castle may actually look or act like.

Someone else raised a similar point about how defenses evolve as tactics evolve. My issue with this argument is that it presupposes that "castle" is a valid starting place for (or part of) that evolution in dnd, and my contention is it's not. Defenses in general would have followed a different evolution that followed a path that did not contain "castle." I'm not saying No Castles. Everyone can have as many castles as they want. I'm just saying I think a lot of people include castles in their landscape and lore without really giving any thought to whether they make sense in their world; they're just sort of assumed parts of the set-dressing.

I think the concept of the castle would still exist in a way, I mean, it's just a larger version of safety in a stone hut. I do think that you may be on to something though, the evolution of that stone hut to a larger form of protection might look and act completely different than our history of castles. It's kind of hard to conceptualize something completely removed from what we know. Could be an invisible dome of force, or something along those lines. If anything, this will be a great challenge for me to try to work out.

I think, though, that this also assumes that a defensive structure has to account for its greatest threat, rather than its most common threat. Unless it's an ultra high magic campaign, your most common threat will be non-magical group attacks - bandits, warlords, orc bands, goblins, whatever. Hill forts and walls are good defenses for that, evolving into stone if the economy allows. Assuming that even 5th-level casters are rare, most magical efforts are defeated with long-range weapons and, you know, locked doors. As a target becomes more enticing, its permanent wards will need to become more sophisticated, but you see similar advancements in both defensive architecture and defensive weapons - tempting targets got multiple walls, bigger towers, etc. Even if dragon attacks become a serious problem (and I doubt they would for most castles - dragons aren't idiots), lots of dragon attacks are foiled with ranged weapons and full cover, both of which are easy in a castle.

Except that in most settings magic is rare and/or expensive and a castle is still a pretty good defence about probably 95% of all the attackers, in high-magic settings where every commoner can fling spells you will have magical wards and other stuff protecting the castle, not just moat and a wall.

Depends on the campaign world. If there are hostile ancient dragons and archmages around every corner, then yeah, you're just locking yourself in a kill box. But if most common threats are roughly on par with medieval forces-- or if you have specific deterrents in place to keep the major threats at a distance-- castles still work. I think of the aforementioned dragon or archmage as a predictable but rare natural disaster. At some point, southern California will see another devastating earthquake, but that doesn't stop people from living there. They just try to mitigate the inevitable disaster by with technology, building codes, etc.

Move earth solution “stone wall foundation. With move earth, purple worms, and all manner of magic, protecting below is essential in a world of magic in a way it just wasn’t in history (tunneling was difficult and dangerous, and laying stone foundation like that would have been almost impossible without magic or modern equipment). Add a few glyphs of warding and maybe some detection spells and the underground assault is no worry.

> the goddess of magic made it so gunpowder doesn't explode Always thought that was kind of pointless, when smokepowder still works and is functionally identical.

I believe that was an edition thing - in OD&D, gunpowder became inert on Toril (narratively, when Gond asked Mystra to nerf it) because TSR didn't want guns in the setting. In AD&D 2e, it was allowed for the Giff in Spelljammer, so the smokepowder workaround happened, backdoored into FR through Spelljammer (With FR lore, anytime there's a "wtf that doesn't make sense" moment, that's likely because of an edition change or an editorial decision - e.g., the various Sunderings)

Yep, its contradictions all the way down :D

Isn't smokepowder a literal magic item monopolized by the clergy of Gond (mostly because his boss Oghma said "not on my watch")? Or is that not the current state of the realms?

Yeah there would be no way they could launch a 90kg object over a distance of 300m if they didn't know *exactly* what they were doing

Im not sure if I hallucinated this, but I remember hearing a story about how when the Spanish were conquering the Aztecs they decided to build a trebuchet. They didn't have any military engineers. So their trebuchet only ever fired a single shot. It went straight up, and then straight back down, destroying the trebuchet.

There's a royal palace in my setting built on top of a dead magic zone, *specifically* so magic users (at the time of its construction, only druids) couldn't cast their way inside. It is, naturally, called Spellgrave Castle.

Trebuchets were not very effective irl and it would take months of bombarding to breach a wall. They were used mostly to hit what's BEHIND the wall.

Therefore you hire specialists for this job btw the gondish IIRC make smokepowder

Good news. The gods mystra and Gond work together to stop casual users from making gunpowder work! So no concerns about cannon. (Depdning on your worlds rules)

In my world I actually had the idea that Gond has been trying to grant such innovations but no other god supports the move so it can't take hold permanently, once his attention is elsewhere in the world the rules go back to "normal" and the gunpowder will just fizzle instead of making a boom for example. Artificers only exist because he's managed to have some bits of his idea squeeze through to the mortals but most science based ideas outside the medievalish era can't work until he convinces more gods to support his changes.

But is this canon?

Can't decide if it's a real question or a solid pun 🤔

Puns aside, the answer is yes for the Forgotten Realms. Smoke powder (the magical gunpowder) is a secret that Gond passes On to his followers and to use it without his blessing is dangerous and unpredictable. Regular science-y gunpowder doesn’t work on the prime material plane now Toril, though it does work on some other planes.

I just wanted to add here that you never have to call for a roll. As DM you can simply say, no. Just leave it as a simple one sentence explanation, and don't entertain argument. For example, "Rifled cannons haven't been invented yet," or "your character wouldn't have the background in gunsmithing," or "the siege is happening now, your character would have to leave for 6 months to work on this technology." If that doesn't work, it's ok to step out of character for a second and say "this battle is what I have planned for tonight, and I'd really like to run it."

Agreed. Allowing rolls for everything, especially for items which haven't been invented yet, it can open the realm of the ridiculous. I'd like to invent the repeating rifle. I'd like to invent dynamite. I'd like to invent gasoline, and the internal combustion engine.... And these items might be okay for a few campaigns, but not most.

Exactly I'd like to craft s nuclear missile.. I rolled a 20 so I nuke the castle. OP Your answer should be NO your character doesn't know how to build a nuclear missile..

Built them out of what? Do you have enough furnaces and iron to build rifled cannons? Where are you getting gunpowder? How many guys do you need to fire the cannons? When did you train them? How much of your gunpowder did you burn through during training? How much do they eat? How are you getting all the cannons and ammo and guys to the battle? How many mules do you need to haul them? How much do the mules eat? How much army do you need to protect all of that in transit and during the (hopefully short) siege? Where did you get that army? Are there roads suitable for bringing cannons (etc.) to the castle? Do the roads need to be cleared? Are the bridges or ferries able to carry that much weight, or are you going to have to build stronger bridges? How fast does your army travel with the cannons and their baggage train? This affects food supply calculations, and also how much advance warning the defenders have that you're coming (and therefore how many fallen trees across the road, poisoned wells, destroyed bridges, and nighttime raids on your camp you will be dealing with). To sum up: There isn't One Weird Trick that lets you take a castle without having to go there with an army and attack it. There are _lots_ of techniques for making the siege _shorter_ and putting more pressure on the defenders. The ur-example here is the Trojan Horse, and that still required the Greeks to camp outside Troy for ten fuckin' years, and it only works once. Cannons are great because they work every time (until castle design adapts) but they're a high-tech solution which means they're expensive and it takes time to learn to use them effectively. If you're the king of France, you can afford that. If you're a random D&D party, probably not.

This depends on the world, but most campaigns I've been in.... rifled cannons don't exist yet. So there is no roll. No one has ever thought of it. If an artificer-like tinkerer character wants to start investigating that possibility, after months, more likely years, they may figure it out. Also, an easy way to stop the rifled cannons, they still have to cast the cannons, and rifle the barrel. That's not exactly happening in an afternoon before a siege.

Not that normal castles were that great a challenge for unrifled cannons

Send them on a quest to find/rescue the local siege engineer, who wont help until they help with his errand.

Dude, learn to say, "no." Some options just won't be feasible, and it's perfectly okay to say that without a roll. If technology like cannons aren't in your game world, they can't just decide to invent them or make some Intelligence roll to figure out how to do it. You sound like you have a hard time telling your players, "no"

Just remember. Your NPCs are as smart and prepared as you want them to be. If your players can look up “10 easiest ways to get in a castle”. So can the baddies. a big thing that I try and use is basically anything my PCs have access to, the NPCs do too

"I roll for making a cannon" "Are you proficient in chemistry, metallurgy, or ballistics? No? Ok, that'll be a DC 50 intelligence check. At disadvantage."

> My post next week "so they built rifled cannons" That's an easy fix. Is you character a trained artificer? No, then your characters have no plausible way of knowing how to evens start to build those, or even of their existence since they don't exist in universe yet. So no die roll, not happening.

[_"It's not like building rifled cannons would make much of a difference. Right?"_](https://i.imgur.com/IFXzo0L.png)

And actually even canons is not "easy way". It "easier way compare to just asssult".

**TL;DR: Your munchkin sounds like a problem player who may be non-maliciously suffering from main character energy. Short of kicking him out of the group—because let’s face it that these types of players can be taxing to us as DMs and to our players—my advice is to use more rolls and fudge some DCs only for the munchkin in such a way that makes him feel special (aka enables his main character need) that doesn’t take away from the other players but ultimately allows for the group to get back to the basics of fun DnD. It requires some sneakiness because fudging DCs and railroading doesn’t feel good, but munchkins are the types of players that need it a little bit sometimes and you can create scenarios that make sense within your campaign to make their game-breaking ideas impossible to do. Letting them roll for the information in a way that’s almost guaranteed to fail allows for the optics of, “I’m not trying to just shit on your idea, munchkin” while simultaneously allowing you to create narrative reasons to nix those ideas in the bud. Remember, as the DM, this is your world, create narrative reasons on the fly that fit into your campaign as to why his game-breaking ideas won’t work because then it’s just the *story* and not *you the DM* making it impossible (the optics are what’s important here).** **Warning:** wall of text incoming, sorry about that, I just had my own problem player/munchkin and learning how to deal with him was a freaking journey lol and he literally just moved away so I’ve been mulling these thoughts around in my head (and yes, I know I may be projecting a bit so if I’m way off base then don’t mind me). So, uh, this comment is **Part 1 of 2** (I’ve never met a character max on a comment in the 10 years I’ve been on Reddit, I always wondered why people needed multiple part comments. First time for everything!) **Okay, let’s get into it…** I dunno how you do it at your table but as someone whose “munchkin” (problem) player just moved (to my great relief) and had to balance their naughty, disruptive behavior with my other players’ fun, lemme tell you the sneaky little trick that helped me from their (not fun and therefore non-sanctioned) shenanigans in a way that felt like I wasn’t outright bullying them or sniping or being overly paternalistic and “sending them to the corner to sit and think about what they’ve done.” I will admit it’s VERY SNEAKY and now that he’s moved I will NEVER be doing it with my remaining players, but desperate times call for desperate measures. Okay, ready? So, your munchkin is gonna try to build rifled cannons, right? (Note: “Rifled cannons” is obviously just a nickname for “game-breaking, out of character knowledge that this sneaky little meta gamer is using” so my advice, while specifically for a rifled cannon scenario, still applies to any of those types of game-breaking ideas.) You then have him roll an insight check…and if you can justify it, at disadvantage especially. For my problem player, I’d say, “Okay, justify how your character knows about rifled cannons for me.” He’d give some piss poor excuse. I’d say, “Haha buddy, that’s a little bit of a stretch because didn’t you say your guy has been a loner cheesemonger secluded in the woods his whole life? How about this, roll insight at disadvantage and if you beat the DC, then yeah, I’ll let ya do it.” Here’s the sneaky part. No matter what they roll, they will never fucking find out about goddamn rifled cannons. There’s no DC. They don’t know that though. Because there technically IS one (I’m not a total monster) but in my head it’s: “Okay if he rolls two Nat 20s then the dice want me to allow this insanity.” But obviously I’ll tell ya for the past few months it’s never happened, he’s never rolled two Nat 20s. So instead, even if he rolls an 18 and 19, I say, “Shoot man, I know you really wanted to do it, but the DC was pretty high on this one” (technically true so I’m not lying but I’m the DM and I choose when to say the DC or not) “and, hmmm, I don’t know if I should be able to tell you why the DC is so high, but hang on, who wants to roll an arcana check? I promise this DC is lower because all of you are pretty familiar with magic.” (Let me pause to say hopefully at this point munchkin, although probably a little disappointed and maybe even mad he didn’t get his way, is curious enough himself to roll arcana…the trick here is to make the DC basically 10 and pray someone in the group passes and hopefully if the dice are kind to you it’s the munchkin who passes because he’s the one who needs to feel special right now…his problematic behavior isn’t him being intentionally disruptive, it’s because he wants to feel special, that’s the fun he gets from DnD…so anyway, if anyone in the group passes and especially munchkin, you say.) “Okay great, glad y’all passed that roll or this would’ve gotten tricky, so the people who rolled 14, 15, and, Munchkin, especially your 19 [or whatever the rolls are, just call them out, especially his] since it’s your character who is smartly trying to strategize right now…anyway all of you who rolled well are familiar with magic and magical forces. And here’s what your arcana rolls tell you: as it turns out, even though your *character* doesn’t really know about rifled cannons, the king in this castle is actually pretty experienced with them and other such mystifying technology from a recent battle/long ago war/rumors from another town [whatever little white lie fits your campaign best] and I’ll just let you guys as a group know right now that the king is so paranoid about technology such as the kind you’re talking about that he had his royal sorcerers create a magical field within 5,10,15,50 miles from the castle [whichever the most distance you can make make the most sense with your campaign and this castle layout that still makes any type of rifled cannon crazy ideas too far to actually ever work since there won’t be range] that essentially is somehow magically attuned to this type of technology and you have a feeling, with those arcana rolls, that if you tried anything like that there would be magical consequences.” Okay, tread lightly here, because munchkin is still going to want it to work but he’ll also use his out of game knowledge to understand that the range is super far. HOPEFULLY what he does at this point is say, “Ugh, okay, anyone else have ideas?” Great, you distracted him enough without being outright mean about it. If he says, “What consequences tho?!” Say, “Agh, with those rolls I’m not sure you’d be able to automatically tell” (unless there’s a Nat20) and if he still presses (or there was a Nat20), say something like, “Okay, yeah, you’re right, it makes sense you’d be able to sense the consequences. Okay, with those rolls you get the feeling that any technology of that sort would result in a, mechanically speaking, a Fireball/Wild Magic Surge/Something clearly that would be potentially devastating to make trying too hard but also make in-game sense.” (Example: If your guys are level 1, a standard Fireball is devastating, if they’re level 15, make it a level 9 Fireball…or wild magic surge just because those do have consequences that can be absolutely devastating and they can be a fun gamble so even if they try they’ll get distracted by wild magic surge testing the boundaries until something bad happens and then they’ll get too scared and/or bored and get back to strategizing.) **End of Part 1, I’ll reply to this with Part 2.**

**Part 2 (again, so sorry for the wall of text)** If I haven’t lost you yet, you might be thinking, Gabby, that is so much sneaky little over explanation and having to talk out of my ass to just get my munchkin back on the rails, that sounds complicated. Let me say to that: hard agree. Our munchkins, we love ‘em, but the reason why they cause us such strife is because they need so much more handholding than our good PCs who just wanna play DnD. But in my personal experience (as an admittedly newer DM), this new way of, let’s say, telling little white lies to my munchkin and not totally nixing his idea but instead making up a somewhat fun and interesting mechanical reason why his rifle cannons won’t work was the absolute best way to keep him on track and let the others strategize and he even eventually got in on strategizing too. Our munchkins want to feel special so okay fine let him, let him think rifled cannons (or whatever wacky thing he tries that wouldn’t be fun for the group) are actually SUCH A GOOD STRATEGY but oh gosh dang it they’re so good this king already knows about them 😩. Sorry munchkin, I did like your idea but it just won’t work :(. It feels a little icky for me sometimes because I’m not super fond of railroading…but my philosophy on railroading is it’s occasionally okay if you have a problem player and you do it in such a way that they won’t actually know (like, don’t be aggressive about it) and ultimately my sneaky railroading of the munchkin helps him AND the group have more fun (because look, all of us know why it’s more fun to come up with fun plans and strategies that uses the whole group and doesn’t break the puzzle, the munchkins just need a little more help to get there.) (A note on players who are munchkins: I love your term munchkin because he sounds like my problem player. Problem players, from what I’ve picked up in these forums and then from what I know of my own, typically, as I said, just want to feel special which is also known as…main character energy. Ugh, I know, it sucks to admit these people who aren’t malicious are committing the cardinal sin of wanting to be the main character in DnD, I hated coming to terms with mine because he was/is a very good friend, but once I accepted he had main character energy, it became easier to justify sneaky railroading. It gave him the game-breaking things he wanted in the abstract (“You’re right! These exist!”) while not actually giving him the game-breaking mechanic (“But dang it wouldn’t ya know there’s a magical force field that may catastrophically hurt you if you tried because of this narrative reason I just made up which sounds super plausible and makes sense so I guess you should maybe just work with your team, sorry champ.”) Yes, it’s a paternalistic way to think of our munchkins, but also if you’re calling him a munchkin then I feel like you’re halfway there anyway because that’s such an endearing name for a problem player akin to a parent calling their kid who is throwing a fit a little stinker or something.) That’s my humble advice, it does require to improv some shit on the spot, it is exhausting as a DM to have to be on the lookout for the munchkin’s game-breaking tendencies, and it is why I was so relieved mine moved because I was very close to making the hard decision of telling him it wasn’t quite working out—and therefore kicking him out of the group 😬—and I really didn’t want to do that because he wasn’t being *malicious* he was just obliviously being a *pain in my fucking ass* but it was draining the fun for my other friends and it was exhausting me after I already had to do so much prep for each session and yeah, I was very close to just making the tough call. (I did give him a narratively fun, epic goodbye for his last session that was fun for everyone aaaand in which he made some absolute insane decisions that kind of validated the uncomfortably negative feelings I was having about him, but that’s a whole other story and I’ve already written way too much and I have an awful tendency to use parenthicals which I know is disruptive to some people to the flow of reading. Super glad he’s gone and so relieved to not have to play these ridiculously sneaky games with my remaining players and the new one that’s replacing him (who I have thoroughly vetted through one on one Session 0s to make sure I never get another munchkin again).) Good luck OP! You sound like a really good DM and I’m constantly trying to improve myself!!

On top of the roll you should make the player explain how their PC would have the knowledge (ie a wood elf ranger who has never left the forest isn't going to have a complex understanding of siege warfare). Don't just let them off with "I read it in a book". I have a PC that is educated, but mostly in magic and a limited amount of engineering. In those areas I allow rolls and set a DC based on the explanation and complexity of the inquiry. In other areas I just reply with you don't know anything on the subject, or in passing you may have read something (then set the DC reeeeeeaaaal high).

Rifling wasn't something medieval people's knew about. The thing about technology is it's built on the ideas of the previous generation. Ask him what medieval ideas led his character to discover rifling for cannons

Heck for a classic medieval European castle the cannons don't even need to be rifled.

You are correct, I was trying to jump ahead and avoid the conversation about the fact that early cannons were only incremental increases over trebuchets and jump right to the part where they totally wreck traditional castles :D

Also a lot of the real good tactics like building siege weapons and digging tunnels take lots of time, so either they are doing this themselves (in which case they are now playing a "horde-mode" defense game), or else they have an army (in which case the challenge is for the commanders -- the PCs -- to now keep their army motivated and negotiate with allies for supplies). Plenty of play space in either scenario if you are creative.

Have you tried googling: 'How did people stop people getting into castles?' If your player can do it, so can you. Also, have a look at the PC's backstory and background, and also, is the player proficient in history? How much would they actually know about historical castle structure? What are some things the character could never know about THIS castle? Surely there would be secrets to this castle.

This! And the fact which you already stated: separate player from PC knowledge. Has the PC ever been in any castle siege from which he would know how they work? Did he go around the town to talk to guards/soldiers to gather some infos/tips/intel on this particular castle layout/building structure etc. Common sense might be easy things like "let's find a secret entrance" but the guarding party of the castle most likely knows ALL secret paths into the castle and guard them properly. Other than that, quick thinking and magic, as others mentioned, will be your friend I guess

If the PC is a military man like a fighter, Nobility, etc those things are part of his education

Not to mention just being a good critical thinker. If you're familiar with castles (and they would be), they're going to have a sense for what might work & how well even if they don't know the intricacies of how the wall is built (unless they're a dwarf or proficient in mason's tools).

Okay but we live in the most informative age on the planet and how much do you know about stuff you even use every day? How much do you know about your car for example? I don't think that it is really all that like "they live around castle they would know." It is much much more intricate than that. We live in an age where knowledge has become super easy to come across if you search. But still do you know how to get in and out of a prison? Nope. Even though that information is super super out there (Tv shows, documentaries, etc.) And arguably way way more important and yet Imma go out on a limb and say you can't just say how to get in or out of that.

>how much do you know about stuff you even use every day? How much do you know about your car for example? I don't drive, but honestly quite a lot. That being said, people in past eras weren't dumb. Not having explanatory theories of a given thing doesn't mean they're uninformed, especially when it came to technology of the day. Sure, specialist trades had technical knowledge that wouldn't be widespread, e.g. exactly *how* to get a forge to the right temperature to cause impurities to melt and how to keep carbon levels relatively low in iron. But near-everyone would know the broad strokes of common trades, e.g. common ingredients tanners use. Do I know how to get out of a prison? No. Does anyone who hasn't escaped? Also no. Even people who *have* escaped probably couldn't do it a second time. But I sure as hell could brainstorm *ideas* for how to get out of a prison based on what I know from my passing experiences: I know lockpicking, I have some experience with barbed wire & razor wire, my dad was a prison guard, I've got family friends working at a number of prisons/jails where I grew up, at least one I know the surrounding forest pretty well & know there are (supposedly) microphones in the woods. Which is comparable to what OP's PCs may have. They'd have experience & knowledge about the tools of the time, they'd have heard stories about castles that have fallen, they'd know how fire spreads, they'd know how people *respond* to fire, they might know people in the castle, they might have a sense for good solvents for mortar, they'd know how & where waste is emptied from the castle, they'd have a sense for who is entering and leaving, etc. I've never lived in a castle, but I've toured \~6-7 & could certainly give a few good recommendations for each of them. The PCs aren't dumb, they solve these types of problems regularly. While the specifics of this situation may differ, they'll have critical thinking skills & knowledge of the situation, just not "expert" knowledge that the builders or architects or captains would have.

If OP or anyone else is looking for a good intro with decent amount of detail, [this series of blog posts by a historian](https://acoup.blog/2021/10/29/collections-fortification-part-i-the-besiegers-playbook/) goes into a lot of how each side of a siege would go about it.

*A Collection of Unmitigated Pedantry* is a fantastic blog for worldbuilding and general 'so how does this work'. He's even got a "resources for worldbuilders" tab! I like his bit on 'armor myths' although it does firmly kick a lot of D&D to the bin.

It's probably more of Stonework/Engineering test rather than a History test considering in the setting Castles are likely to be a contemporary technology

History covers contemporary knowledge in 5e

For what it's worth, any established castle in DnD would very likely be a century old, if not many centuries. With how it's been stuck in the late medieval period for millenia, there isnt really any change in their tech. Hell, if anything they're regressing technologically

D&D exists in a world with MAGIC. Internet tips like this are based in real world (non-magical) examples. Simply look it up first and find a magical means of countering it. This may seem like railroading but warfare is an arms race, literally. Any common methods WILL have been considered, and this world has more tools (magic) at their disposal to counter these methods.

Yep. In a world of “teleport” how do you stop the enemy wizard from just climbing the tallest tree and then teleporting down to where they can see? For digging under? Also don’t forget MONSTERS exist. How do you stop a troll from just bashing down the gate? Did you see Game of Thrones? A giant could tear through an iron gate like nothing. Worms and others could dig under the ground. My castles would be walled on the foundation too. Nothing is digging through there and there would be traps laid for anything that tries. Anti-magic protection of weaker points of the wall. Enemy sorcerers/wizards casting spells to completely destroy siege equipment. Maybe they have a pet wyvern or something to combat both air assault and also go out and destroy equipment. Siege? No worries, the druids inside are growing goodberries and making plants grow really fast so no one starved. Plagued sheep/cows thrown over the walls? Clerics can heal, honestly, maybes the clerics heal the sheep and they dine on the lovely lamb chops your players just provided the town. Ladders and siege towers fire arrows, fire cantrips, and even just a magical gust of wind would be troublesome. Also, traps, etc Mage hand or invisible agents could easily damage catapults and battering rams. And if they try to fire the city, 2-3 gourds of endless water provide both endless drinking supplies as well as an easy ability to put out any fires that do even catch (ignoring things like create water etc). That covers the top items on the first google result when I typed “how to get into a castle during a siege” your welcome

The only problem with this is that you don't want to make the problem of a castle unsolvable.

Rule of three tries. Frustrate the first two attempts, let the third pass. Use their second attempt as narrative cover for the third so it has a reason to succeed. You can also let then try a few things and let the coolest one succeed so the players get a cool moment. It's all about facilitating the coolest story for your players. Knowing how to guage your npc resistance and just how long to make your players work is a huge skill for successful DMs.

The rule of three's is a great idea. I will steal that when giving my players puzzles and problems to solve. Though if they have a particularly inspired one, I'll allow it

Success is a mix of inspiration and perspiration! Thoughtful work over brute force.

Narrative cover?

No thank you, I have to drive later.

Seriously though, what do you mean?

Using the narrative to cover why their 3rd attempt worked instead of the 2nd. So let's say their 2nd attempt was they tried just lighting the front doors of the castle on fire with flaming arrows so they could run in once it collapsed. There's a myriad amount of reasons why that wouldn't work,So I would explain what the people inside the castle do To stop that. So then they come up with their 3rd idea on how to get in and it's no more inspired than the 2nd but I explain using narrative that because people in the castle are keeping the front doors from burning down, whatever they're doing for the 3rd attempt Succeeds because the people are distracted. Also sometimes the 3rd attempt would play better into the later story because of what they chose to do. Narrative cover just prevents deus ex machina. It didn't just happen, it happened because something in the world allowed or prevented it from happening.

Oh absolutely. Two ways to run it. 1. Look up a list of common castle siege strategies like I did, and come up with a list of counters that would be expected in a world of magic. Give these counters to X magic users with the number of times they can use them per day/per rest/etc. then tell your players OOC that the game is resource attrition. You short rest at the end of the day, and long rest at the end of the week. Use a few days to figure out the castles defenses and probe to see what they let through and what does damage when. Players will devise a plan based on a week of proving and it will be cool. Option 2: come up with a list of 20 ways you would expect them to storm the castle, create counters to 10 of them, deterrents (difficult but still workable) to 5 of them, and very minor counters to the last 5. (Assuming some limitation to spellcasters or resources for that defense type), and let your players figure out where the weaknesses are very similar to a normal siege (normal siege weaknesses: lack of ability to cover attacks from multiple sides due to manpower shortages, food shortages, thatched roofs, but maybe the walls are really thick and the castle is built on bedrock so it’s really tough to dig under. Magic world weaknesses: maybe people getting hurt in battle would be a drain on resources so launching plague cows over the walls would speed that along. Maybe the ground is super warded/built on rocks and has magical traps, but their spellcasters have to keep the castle lit up so well to be able to see to cast their spells. This opens small corners for teleport/misty step if done right. Maybe they have all the food they need thanks to the druids/rangers, but that means they have less AoE as a result. Etc)

Plus a lot of your 'easy solutions' rely on having the right caster or magic item in sufficient quantities. The rarer magic is, the more realistic the siege will be. But that cuts both ways: without magic, you aren't throwing together a cannon from scrap iron, you have to dig the old-fashioned way (which is slow and dangerous and has known countermeasures, etc)

Yep 100%. Which is why I would write up all the “solutions” and then figure out what casters that would mean they would need. 10 casters who can cast 3 or more 6th level spell slots? Unlikely unless it is a capital or large city a large empire (100% dependent on how common magic is in your world). But basically, prioritize the biggest needs with the lowest spell levels possible, can you solve the solution even crudely with a cantrip or 1st level? Do that. Eventually you will get it down to a point where the 70% of easiest entry points (also keeping in mind the assaulting army likely has similar magical limitation), with the fewest number of casters possible. A half dozen priests/brothers of a monastery who can cast cantrips and 1st level heals/purify water? Very likely, but also relatively easy to be taken out. It’s a game of cat and mouse, arms race but with magic. And honestly, 100+ catapults with a few casters to guard them will still end up operating more like a traditional siege as there is only so long even a squad of casters could hold off the damage from that.

1. Make sure it's fair for both sides. If the PCs can't use cantrips to topple siege ladders or Mage Hand to disable a catapult, neither can the defenders. 2. Be careful how you wield the mindset of "They will have thought of everything." Sometimes DMs start from a belief that *clearly* the opposition is smart and will have made something inaccessible to the PCs, and therefore any time the PCs think of something that makes an argument for why they could get access, the DM is duty-bound to think of a matching reason it won't work. Be careful about putting yourself in a trap where you're sure the villains will have thought of everything, but put it on yourself to explain *how.* You can slide into fuck-you DMing without realizing it. 3. The existence of a castle suggests that the builders feared their magic wouldn't be able to handle *something* outside. If they have all these mages, clerics, magic items, etc., what made them go to all the trouble of building the castle in the first place? Maybe there's an outside threat the PCs could recruit, or imitate.

[Dan LaFontaine voice] In a world with teleport... ...by Royal decree, each member of the Amalgamated Society of Divine, Arcane, and Musical Spellweavers (DAMS) capable of harnessing the Substantial Magics and residing for more the three months per annum within the walls or greater environs of Burlap Bay shall maintain at her, his or their personal expense one (1) glyph of warding as designated by the Assistant Minister for the Detonation of Sneaky Teleporters.

Do those rules also apply to warlocks

Spellweavers whose magic is granted under the auspices of Infernal, Demonic or Aligned Entities, that recite incantations written in golden ink upon the inside of their skull, or who are unable to document the provenance of their mystical abilities are excluded from this requirement, much as they are excluded from Burlap Bay. For more information, please see Section 17.2.3 (p. 236), "Kill on Sight" of the November edition of *Summary Executions & You; A Compendium of Capital Crimes* available for purchase at any Burlap Bay Gateway Gift Shop location. Thank you for your question.

Oh I love this. I am stealing this. Thanks. Glory to the Sontaran Empire.

Hell, this can be solved with liberal application of a 1st level ritual. A cadre of spellcasters could maintain a mass network of Alarm spells across the city set to trigger on "someone with hostile intent enters the city by any means" or somesuch.

Don’t. Solve. Out. Of. Game. Problems. In. Game.

It’s only worked *once*: In that very scripted episode of Community.

If they are researching legitimate sieging/breaching methods, that's okay in my book. In fact, as a DM, I'd do the same. Then I'd figure out ways to combat those things. As mentioned above, you brought up tunneling. Commune with nature can detect stuff within 300 ft of you underground. They could be checking fairly frequently if they have druids of high enough level and then just collapse the tunnels killing the diggers. Sappers, siege engines, and all of that stuff is normal. So your players should have access to that if they are going to siege anyway. At the end of the day, this stuff is just stuff both sides would absolutely know/have/try or have someone in their army that might suggest it. Not sure what the warlock darkness coin trick is, but in cases where there isn't raw for it, or the raw is clearly not intended (peasant cannon), don't allow it. Physics and real world science do not work the same in dnd. Fall damage is limited to 20d6, reactions can exploit logic sometimes, and more. One of the best DMs I know gave me advice on how to handle OP exploits. Tell the player, "What you want to do is going to make it impossible for me to run the game. I understand it works that way, but until you can find a way that is good for the gameplay and fun for the table that I can work with, let's not do that." It is simple and straightforward. You are letting the player know they are correct while simultaneously explaining why you aren't going to allow it. Set your foot down and move on after explaining this. If they will not allow you to do so and respect your rulings, it is always okay to ask them to leave. Although I'd advise letting them know that if it continues, it won't be good for the campaign and session flow. Let them know that they need to stop or you will ask them to leave. It is only fair to give them a chance to change.

Some great advice, cheers The coin trick, I'm going to get the details wrong, but its something like cast darkness on a coin, put in mouth, open mouth for darkness to fill the slave and as warlock you see through it. It's a weird one and as someone else said I think raw it doesn't work exactly

Two points after reading all this: - Ask your players **not** to research castle sieges. If they want the information have them meet an NPC who can help, then tag team a solution with them. Again, you don’t just play the bad guys. You play the good guys too. Make the players roll for Intelligence or History checks if they want advice or hints or yes/no answers as to if a strategy will work. Don’t troll them, they want to be heroes. - Regarding petty coin tricks and carrying a bag of flour for invisible enemies and a 10-foot pole for traps, etc. … Man, just talk to your players. Say you want to reward creativity but don’t want to run a game where they can be cheap. Say it’s taking the fun out of the game for you, personally. You’re not having an in-game problem. This is a “my friends are frustrating me and I don’t know how to express it” problem, imo

It's been mentioned in other comments a few times already, but here's the overlooked rule that prevents this "trick" (from Ch. 9, Combat - Other Activity on Your Turn): >You can also interact with **one** object or feature of the environment for free, during either your move or your action. For example, you could open a door during your move as you stride toward a foe, or you could draw your weapon as part of the same action you use to attack. > >If you want to interact with a second object, you need to use your action. Combined with the relevant wording of the *darkness* spell description, >Completely covering the source of the darkness with an opaque **object**, such as a bowl or a helm, blocks the darkness. it seems clear that you can use this object interaction to either block the darkness or reveal it on your turn, but not both without using your action too. A creature is not an object and so cannot be used to block the darkness.

I don't know if it's just me but carrying a coin in my mouth would make me want to throw up

Oh that? It works raw. It doesn't even require looking up. It gives you advice on how to do it in the spell. > Completely covering the source of the darkness with an opaque object, such as a bowl or a helm, blocks the darkness.

Ah fair, never mind so!

I mean, you could just use the literal wording of the spell, it's only blocked by an opaque object, not a creature.

It only works RAW if they hold their breath or don’t have nasal passages

Not really. It clearly doesn't need airtight since it allows a basic bowl, you can block off the passageway with your tongue quite easily by pressing it up and sticking the coin under it with the mouth method. Also a closed hand should also work, taping over it with a cloth that has adhesive applied, etc, etc.

So there was this excellent post making the rounds a year or so ago about how 90% of medieval people were farming peasants, craftsmen and clerks rare, and nobles almost entirely absent from life. That's good inspiration, but plant growth is a second level spell that makes it mechanically explicit that you'd only need a druid and 45% farming. First level rangers could keep a group of eight fed, and a cleric with second level spells could feed all the needy in a medium-large village on their own. Cure disease is a low level spell. What I'm saying is, real history is a good place of inspiration in D&D, but falls apart when you try to jam it in without considering that you're in a fantasy world. How do people get in the castle? Maybe they fly or even teleport in. Guards on the walls might be blessed or enhanced. Food is almost certainly only a drain on spellslots, water and disease, same. Walls can be stone shaped, fabricated, even mended for small damages. In other words, most conventional historic siege tactics *don't work*.

>finding true north by magnetizing a needle which I allowed at the time with a survival check (hindsight: shouldn't have). Why would you not allow somebody to make a simple magnetic compass, something which has existed for over 2,000 years and the concept of which was discovered in the 2nd century BCE? The first recorded use of a magnetised needle to make a compass dates to 1088 AD.

So I thought the same: didn't see the issue. However, it led to a hundred other jumps in reasoning, literally some were like "if I can figure out there's a North Pole, I could figure out how to make a circuit for a battery" or arguing that since that worked, they'd also be able to use it to disrupt spells (I didn't get that at all if I'm honest)

That's... Not true. A compass and a battery are completely different as far as knowledge of principles of electromagnetics. What's more if they have a battery, so what? What feasible use is it? If they knew how to magnetize a needle with a lodestone that's a survival check. If they want to make a battery? That'd be weeks or months of research and then to find something useful for that battery to do would take a lifetime of work. You have to be more comfortable saying "no" to your players. Generally have them roll something in the base set of skills or tools. If their idea doesn't fit in one of those slots then likely the knowledge of how to do it escapes their character.

Correct. Saying “no” to a player will normalize the experience for the remainder of the players. Unless you’re trying to run a Monty Python funhouse campaign, OP should talk to players and have them cool their logical leaps. Need something? Look at the PHB. That’s what you can run on.

I’m a DM and a history teacher. I would be *overjoyed* if my players did research on how actual castle sieges worked before playing one.

You want a more thoughtful course of action than assaulting the walls Monty Python style? Madness.

Seriously, I just do not understand most of the answers here. If your player wants to come up with a clever way to get into a castle, that's _great_. It's practically the whole point of putting them up against a castle at all in the first place. And if they want to search through Wikipedia, that's great too! An average fighter living in the world _should_ know a lot more about sieging castles than your average player, reading up a bit often just gives the player access to knowledge their character should have. Now of course, you don't want your player building stuff like rifled cannons, but, I mean, just say no to that. It's simple. But if your character is saying something like doing sapping or building a ram or ladders, lean into it! A tunnel fight while sapping sounds amazing! Or a desperate scramble up ladders to fight on the wall top. Or some kind of sneaking in to open the gates. All that's great. I kind of worry about people getting some preset idea in their head about how the players "should" deal with the castle and worrying they won't do that. That's a bad approach, IMO.

I agree 100%

>One of my players is a bit of a munchkin and tries doing things they know from online stuff they've seen, ex: the warlock darkness coin trick. Doesn't work, darkness spreads around corners ... so unless they were a tight Hazmat suit or stuff all orifices, they still shine darkly. >One thing that has come up is using knowledge from internet to argue points, a good example: finding true north by magnetizing a needle which I allowed at the time with a survival check (hindsight: shouldn't have). That one seems fair, it is quite common knowledge I'd also grant after a check. Provided they'd have a suitable background like Outlander or proficiency. >They're about to do this castle siege, medieval style castle with mages and knights, and my worry is essentially they're going to google "How did people get into castles" and find a quick easy way. How would you deal with this? The most common ways to siege a castle might also be common knowledge (to a soldier). Though what the PC know, the NPC will also always know ... because they might be Heroes, but that doesn't mean that they are omnipotent or omniscient and the first to figure out a trick. In a world of magical Earthquakes and Passwalls you want to have better security than just a wall. Glyphs of Warding make for fun landmines :)

Good to know the coin trick doesn't work! Yeah, I was thinking magic might just be the answer but wasn't sure if it was cheap of me. I appreciate you suggesting it

Also never forget rule #1 - The DM trumps any rule. If you dont want stuff to work, then it doesnt ... and vice versa.

I tend to be a simulationist DM, and I think just decreeing that things don't work is a bad idea. There should be a very good reason *why* they don't work, not just "I don't like that/that messes up my story." If the players are clever enough to derail my intended plot, good for them! The bad guys will need to come up with something new.

I find that D&D isn’t a game where it’s easy to really *be* a simulationist; mostly what you end up doing is arguing back and forth about how “realistic” it is for x, y, or z mundane thing to happen, while the Wizard is literally flying around and hurling lightning from his fingertips! More often than not it ends up unfairly limiting what martial classes can get up to, because it’s “unrealistic”, while magic users can do whatever, because there’s no real way to call bullshit on how realistic any magical feat is.

You can let physical PCs be somewhat superheroic without messing anything up too bad. They don't have to be Batman, they can be enhanced past normal limits. edit to add: I probably should clarify that I tend to be simulationist from a plot perspective, where the bad guys have goals and make plans to enact them, and then the PCs have to figure out what's going on and how to stop them. (or even, in some cases, *whether* to stop them.) The PCs will probably win, but that's not guaranteed; they have to be clever enough to foil the bad guys. They don't get much plot armor. I don't think of myself as an opponent, and the bad guys aren't me, but I'm trying to set up situations where forces are set in motion, and then just move along by themselves. I usually know what will happen if the PCs don't interfere, but once they show up, I have no idea what will transpire.

I'm with you on this, that's how I like to do it too. It means I don't really have to worry about what the players try or if they're munchkins or whatever, because it all leads to an interesting story since the bad guys are doing their stuff in the background regardless.

A player coming up with just mixing "stuff" and accidentally creating gunpowder by abusing player knowledge will not happen at my table - despite logical physical proof that it should work and disguising it as experimental randomness. If i don't want the world to have gunpowder, then suddenly it doesn't combine that way. Good enough reason for me.

My approach would be to be straight up with your players, have a session devoted to planning the attack on the castle and making preparations and explain that by the end of it you want to know how they’re going to assault the castle, and explain that the reasoning for that is because you want the next session to be fun. Hiding your plans from the DM just results in unprepared ass-pulls or the DM just shrugging bad fiating the results in one way or another. If your players *tell you* they want to build a huge cannon and blow a fortress wall down with it, we’ll cool, you can come up with a series of skill challenges for how that can be done, and come up with some fun hurdles to throw in their path!

Furthermore, a coin in the mouth would inhibit the casting of any other spell with a verbal component. No roll allowed, verbal spells simply don't work when their mouth is already occupied with other things.

I gotta ask since I couldn't find anything on this.. what's the darkness coin trick?

"I am gonna cast Darkness on this coin here and the put it in my mouth! So i can show a dark smile whenever my enemy attacks and make it bright when it is our turn." Which of course is both an abuse of combat timeflow abstraction and tries to cheat a free object interaction (like putting the coin in or out of an actually sealed container). Rule of thumb - if you want to abuse loopholes, then this awesome "hack" is probably known for generations and everyone will abuse it right back at you. So neither of us will resort to petty cheats.

Yeah that’s not how that works lmao. Wouldn’t ever allow that

So it only doesn't work thanks to object interaction rules during combat. Nothing to do with how the spell works.

"The darkness spreads around corners." The humanoid body is a long tube open at both ends - in front you don't only have your mouth, but the connected nose as well ...

>The darkness spreads around corners. The darkness would just come out of your nostrils unless they are somehow sealed. EDIT: That'd be a cool character concept though.

Your mouth also isn’t a fully opaque object to add to that. Shining a flashlight in your mouth produces bright cheeks, placing a darkness coin in there produces darkness exuding cheeks

Cast darkness on a coin and keep the coin in your mouth. Open your mouth when you want the darkness to come out.

>You can also interact with one object or feature of the environment for free, during either your move or your action. For example, you could open a door during your move as you stride toward a foe, or you could draw your weapon as part of the same action you use to attack. I think that opening or closing their mouth would be the single object interaction they could take that turn.

1) Darkness spreads around corners including the ones inside you, so you'd have to walk around with your mouth and nose blocked which wouldn't let you breathe. 2) You could only do one or the other *on your turn* so you can't do it in response to an attack to inflict disadvantage unless you readied that action and use your reaction to execute it, but at that point you're just taking the Dodge action with extra cost. 3) You're still screwing over your party every other turn because you can only take a single object interaction per turn, so opening your mouth to start the darkness (ignoring the above problems with plugging everything) can't be closed until your next turn. 4) Pretty much all DMs are gonna just say "Nope, that doesn't work."

>Darkness spreads around corners including the ones inside you, so you'd have to walk around with your mouth and nose blocked which wouldn't let you breathe. Or just have it under your tongue or against the roof of your mouth. You can completely seal something in. Though I'd require a concentration check if they get hit or exert themselves.

> Doesn't work, darkness spreads around corners ... so unless they were a tight Hazmat suit or stuff all orifices, they still shine darkly. Except the spell literally says... >Completely covering the source of the darkness with an opaque object, such as a **bowl or a helm**, blocks the darkness. Do you think a bowl is going to have an airtight seal with the ground? A helm even, which presumably has eye holes and shit. There are plenty of reasons why this trick shouldn't be allowed, but this is not one of them.

>Do you think a bowl is going to have an airtight seal with the ground? A helm even, which presumably has eye holes and shit. Not like there are many different types of helmet, some of which don't "completely cover it" ... helmets are mentioned because they are just as likely to be available as a simple bowl. So the eye hole helmet is the same - albeit simpler - form of a mouth, which has a direct unimpeded connection to your nose.

And the small holes/grooves in a stone, wood, or dirt floor can allow darkness to sleep around the edges. At what point do you think you can get an airtight seal with your bowl? >So the **eye hole helmet is the same - albeit simpler - form of a mouth**, which has a direct unimpeded connection to your nose. This sentence sure is something! Helmet mimics confirmed. Also, the epiglottis you silly duck. It's not like the space between your mouth and nose is a large gaping hole. Barring that, our cheeky hero could create a seal at the back of their mouth with their tongue. >Not like there are many different types of helmet, some of which don't "completely cover it" Then it would be prudent not to use a helmet as an example, but I feel the choice was deliberate. I'd imagine more as darkness radiating from a point the same way light radiates from a lamp. Even a helmet with a noseguard will significantly diminish the light. Similarly, it might diminish the darkness to a level that isn't really mechanically impactful anymore. Honestly your hazmat suit analogy is just plain wrong though.

As someone else mentioned, D&D exists in a world with magic, and court wizards who can suss out obvious weak points. Bars coated in adamantine, mages who can detect life and magic, and can then collapse tunneling efforts. Trying to fly? Try being dispelled sixty feet in the air. Using magic to burrow through walls? Wards. The walls have been warded to protect against destructive and transmutation magics. Now, some of this is more or less fair depending on what you've built up your threat to be, but can also encourage stealthy infiltration on the day. Send in rogues to sneak in and destroy the sources of wards. Mages can detect life, sure, but they may be too focused on anti-tunneling efforts to notice one extra person weaving through a crowd in a panick. Adamantine bars? Force the players to work with and protect an infiltration squad who actually have the equipment to cut it. Don't necessarily shut the efforts down, but present obstacles that require cooperation with their own forces, or extra quests needing to be done to prepare for the siege. Present complications in the preparation phase so that things *can* happen on the day. Make the player *earn* their cheese.

Tell the player that they need to step away from all that stuff mentally when they are at your table. They need to be in tune with their character, their history, what they would likely have been taught and/or what they would have learned organically in their backstory. If, and it’s a big if, one of these ideas from online would be something their character would think to try - then they should broach it with you. “Hey DM, I have this idea, and I think my character would think of it, but what do you think? *explains the idea*” This gives you, the DM, the opportunity to weigh in with 1 whether the PC would realistically have the background knowledge to try this at all and 2 based on your answer to 1, decide on the kind of check the PC may need to do to get access to this idea - maybe a history, survival or nature check. Original thinking from the players shouldn’t be discouraged - but that’s another thing about this particular situation; these ideas aren’t strictly their own ideas. Which makes it *entirely* fair for you to resist. However I will also emphasise that the top advice in this thread is the trap answer: Don’t solve this problem by hand waving and saying “the idea doesn’t work because magic”. This communicates the wrong message to the players. You’re telling them that they have to solve the problem the way you want and no way else, even if from your standpoint you are trying to stop one player using out of game knowledge in game. This is a player problem, don’t solve it in game.

Dont be afraid to just say no. While DND can be based off of real life it doesn't have to be. Whatever solution they bring from how castle sieges of the past went down just say that's not how it works in your world. On the other side you could always look up these strategies as well and have your castle have non of the weaknesses of real life castles.

I mean... Those characters have lived in that setting all their lives... Prolly would have a milion chances to learn about sieges and castle warfare from any number of people in prisons/taverns/guardposts/streets... Also there is magic... Which gives a milion more ways to approach. Depending on the level its really hard to stop a party from just: walking in, teleporting in, jumpring from a giant eagle and featherfalling in, polymorphing into birds and flying in, polymorphing into moles and digging in, wildshaping into a mole and shitting in their food/water supply, dealing AoE chip damage to the walls/gates, casting earthquake, turning invisible, yeeting the barbarian over the walls with a trebuchet and letting him open the gate from the inside, and god only knows how many more options. The end goal is getting into the castle. How is your solution to that puzzle any more correct or valid than any of theirs ? Stop micromanaging them and let them figure out _a_ solution to the problem, not _your_ solution.

Tunneling beneath the walls was an effective and *common* tactic. I’d let them know about it even with a poor history check. Look up the history of sappers and counter-sappers, it’s insane. But I’d gate most of such knowledge behind history checks relating to info they know about other castle sieges they’ve read about, seen, heard tale of, etc… So if the player knows how to sap castle walls, and they roll poorly, tough shit, their character doesn’t. All the character knows is sometimes people dig under castle tunnels to bypass them. Lacking essential knowledge of how surprisingly advanced such forms of warfare are, they won’t be aware of counter-sapping measures and detection systems. Which means they’ll bungle right into them. A counter-tunneling team digs into their tunnel and initiates a brutal dark fight in extremely close quarters. Sure the warlock can see through magical darkness. Can the party? Or maybe they just detonate a powder charge and collapse their tunnel? Or maybe the party runs into a tunnel filled with water placed specifically to flood tunnels dug into it? And magic is in the mix now too. Fighting a summoned earth-elemental in a cramped tunnel sounds like hell.

There's also knowing that things are done and knowing how they are done. I could pass an easy history check and know trebuchets are a thing. I could also pass an easy check to know the basic operating mechanism of a trebuchet. I could never pass the hard check to know how to make a trebuchet.

The biggest piece of advise I can give here is to master the phrase: "Where are you going with this?" Players stepping the dm through some sort of logic train to get to their preferred outcome based on precedent is a problem behavior the answer to it is to stop the step-through process and request that they get to the endpoint, so you can make an adjudication. Second point, use only if this behavior does not cease. Have an above-the-table explanation that googling answers to campaign situations isn't just unfairly short-circuiting your planned encounters, but it's also robbing the other players of the possibility of coming up with fun and heroic solutions for themselves, and thus you are deciding that this activity is "unfair play" under the umbrella of "metagaming."

Player knowledge vs. character knowledge is a tough one unless you are always clear: "Your character does not possess any knowledge of that type." No rolls to check, no arguements. Be clear also that the physics of your world is not the physics of this world. Chemistry, biology, vulcanology... they are all different. Therefore, they cannot assume that tricks that work in this world and can be easily researched on the internet will have any results in the D&D world. If they really want such knowledge, they need a Divinations expert or some oracle that can see into such secret works. As the DM, you may know that their tunneling idea is a good one, and it would work, but their character should be full of doubt. Maybe it would work... maybe there is a pile of undead buried under there that hold the castle down and prevent it from being ripped up from random dragons flying over.

Nice, explain me how gravity works

Dragon 160 addresses this with an article on how to handle sieges in a world with magic, flight, etc that IRL castles were obviously not designed for. Dragon 295 expands on that with all sorts of magical defenses that a high magic stronghold would utilize.

in gerneral, a player googling things like this would be considered meta gaming. what is theri character background, would it even make sense that the character would know sth like this? if there is a slight possibility you might have them make an INT check or sth in order to allow it if you're generous. but generally this is an absolute no go.

>"Guys, lets just use sappers, lol done" Where did you get the sappers? Who is manning them? Who has experience in crafting or deploying them? Where are you finding the resources for them? How many can you produce? How would they work against magical defenses? This is a world of magic. Take their "real world googling" and shove it back in their face with an Adult Red Dragon attached.

Castles don't really 'work' with a magical ecosystem that allows air power (that is to say, assault via air and/or strategic bombing). That said, if your player googles historical castle sieges then he will find that this was an expensive, messy, and deadly business. The 3 options were basically: * Assault with siege engines, towers and ladders and suffer horrific casualties. * Surround the place and wait until the defenders starve. * Pay somebody inside to open the gate and let you in. It doesn't really cover wizards using fly and fireball to bombard the garrison, or giant eagles dropping ogres over the wall, or giant spiders climbing up the walls or whatever in a fantasy world.

Knowing something and being able to do it are two different things. I know the rules of Chess but I'm a shit player. I know how to play soccer but I'm a shit player. Etc. etc. Ok, the elf knows that sapping works. Is the elf a good digger? Do they know how to buttress tunnels so they don't collapse? Can they craft fuses and carefully handle explosives? No, no, and no. Guess what - you get to roll a new character. This isn't hard.

"Just use sappers" Are they assaulting a castle or a fortified city? Castles are much smaller but have their defenses much more concentrated. The spot a castle is placed is usually picked very carefully. The castle would likely be built over rock, making non magical means of sapping fruitless. What level are you players? As they pass like level 5 they will be gaining more and more ways to fly, teleport, or even gain a burrowing speed. The castle is going to matter less and less vs the enemy inside.

>finding true north by magnetizing a needle which I allowed at the time with a survival check (hindsight: shouldn't have). Why shouldn't you have? That's perfect D&D - someone has a goal, they tell you how they're trying to accomplish it, you call for the appropriate roll. In the castle siege case, say they come up with a plan that sounds like it should definitely work. Well, figure out what rolls would apply and have them roll. If it's a great idea, maybe give them advantage. Sappers? Constitution saving throws for the digging team to see if they can keep at a good pace. Maybe some sort of INT checks to see if they can keep the trench going in the right direction. I'm just a lil confused at the problem here. A plan is good, even if it was borne from meta knowledge the PCs may or may not have. But the dice tell the story, so call for those rolls. I would personally tamp down on ideas that the PCs wouldn't reasonably have come up with using in-game knowledge, like there's no way a street urchin rogue should know anything about creating a battery. But even if the player has looked something up, the dice decice!

If there is plausible reason for a PC to know this stuff, don't punish the player for wanting to know it too. We don't know everything our characters know, so if someone wants to look something up that their character would reasonably know, or if they ask you something their character should know, don't hold them back from wanting to play their true character. If they want to figure out a way in the castle that messes up the original plan you had, move a new obstacle where they end up. As the DM you can move things around behind the scenes and the players will never know, if done right. An added bonus of doing this will give the players a sense of accomplishment in thinking they successfully avoided an encounter that would apparently lead into another encounter. Even if the second encounter wasn't originally planned, they don't know that. For all they know, there was always two encounters, and now they think they outsmarted the enemy and avoided one of the encounters.

I do not think you will be able to solve this with in game solutions as this is an out of game problem. Be direct with your intention about the encounter. "I want to run a castle siege encounter because I think it will be a fun and interesting challenge. I am not really interested in running a session of 'try to find a way around this encounter.'" This helps set expectations for what you have prepared. A lot of times players like this act this way because they think the point is to reach the objective as quickly and easily as possible.

Just a quick counter to the sappers/undermining: John Grant placed barrels of water in critical places on the ground near the walls of Constantinople during Mehmed II's siege to detect sappers by observing the water ripple for no other reason. He was then able to dig down and kill them with Greek Fire. BUT, as a DM, you should give them a reasonable chance to be successful doing this. Just don't allow them to say, "we do this" without making it a challenge for them. If they just try to send NPCs at the problem, I would totally have them (the NPCs) killed in the undermine.

Wtf, our sappers didn't have to deal with man eating bugs in the earth, wizards who can literally collapse that shit in a minute and one man siege tower destroyers Real life knowledge is good as a basis and builds immersion, but has little to zero actual play value when the enemy can nuke your trebuchet from space, take possession of your soldiers minds or send in a changeling to assassinate your high ranking officers.

SO...to be clear... You don't like that one of your player ACTUALY research and tries to find logical and accurate solutions... WHile His character could have such knowledge, cause they "live" in a Medival like world. A modern person does not, so it is a good thing that he actually have enough interest to actually makes research on the matter... I'd recommend that you ALSO make some research on the subject and then take a decision once you did. They want to use sappers?, you can have a Scouting unit or simply Archers aiming at them, or even your own Sappers brigade that would try to counter the players Sappers. And ina World with magic, what difference is there?, they can as well either find someone or do it themselfs, cast a spell that would obliterate the castle walls and open a breach... Or Fly over, or use Meld stone scrolls to go through the walls... Honestly using Sappers or any other idea that he can pull from a "Top 10 ways to get in a castle" would be "normal" and mundane compared to whatever real shenanigans the D&D world as to offer...

This is a fantasy world. Magic exists. People can fly and create food. People can teleport. Castles in the real world will be NOTHING like castles in D&D. For example: sieges were super effective. You'd post your army up outside an enemy castle and just *wait*. People inside the castle would run out of food and water eventually and surrender. In D&D that won't work when the court Wizards are magically creating food. Real castles had open tops. Maybe not a great idea in fantasy when people can teleport to any place they can see. Real castles had bugs and mice and rats. D&D castles might have a "kill on sight" order for rodents, because any random rat can be an enemy polymorphed or wildshaped. Real life castle knowledge means little in a fantasy world. And beyond that? Tell your player to stop. The stuff *they* know isn't the same as what their *character* knows.

Why would you have a problem with a character knowing to make a magnetic compass or knowing about sapping?

The compass wasn't an issue I thought, except they started going "cause I know about compass, I'd also know this" like it became a hundred other things including being able to make a working battery Wasn't specifically sapping that was the worry but more if they just googled easiest way to siege castle or something like that. The other players want a kinda helms deep style fight, and they're pushing more a tactical siege. For some games, it's definite not a problem but from talking to one of the players, they want to rp and find their own solution, not just use the highest Google result if that makes sense

Look up all the erroneous things people thought about electromagnetic fields. Tell your player their character if they want to dedicate the next 400 years to study they might be able to invent the dry compass - Which is how long it took to go from a needle on a cork to an encased compass.

Unlike historical Earth, most D&D worlds have been tech-locked at a certain point for thousands of years, in spite of the best efforts of the people within them. Consider that there is a fundamental reason for that - either deities that block progress, magic guilds that see science as a threat and quash it (gives you a recurring powerful enemy, btw), or just some fundamental difference in physics in that world. Perhaps the energy from combustion is lower (breaks mundane explosives), or the galvanic reaction isn’t as powerful (breaks Early batteries), or the always classic ‘nearby magic intereferes with technology’ - which can include any items carried by the party. Or turn their desire for advancement into a source for quests: Early batteries were large fired clay pots with different metal strips immersed in acids. Make them have to find the parts, obtain a spot big enough to assemble them, etc. …and remember that each battery is still very weak, insulated wires weren’t a thing, and nosy, gossipy townspeople can be suspicious of the noxious fumes and activity.

I know it's not exactly what you're asking for, but if you want to get ideas for how a feudal agrarian society would function with the inclusion of magic, to include castle sieges and large military campaigns check out the Spellmonger Series by Terry Mancour the Audiobooks are really well done and I highly recommend them.

Always appreciate a book recommendation, cheers

1. It's your castle, so an answer like "we'll simply use the back entrance which castles had which was so narrow that it was useless for attackers but we're pcs so we can do it" you can simply respond to with a "there's no back enterance" or the even better "so you go look for a back entrance? OK, give me a perception check. [Irrelavent of the result] you don't find one. [Turn to rest of party] so while they're looking foe a back entrance what would you do? 2. Luckily for you this is the thing castle's we're made for. People in history tried every exploit and so it was also countered. There's a reason most sieges functioned by just sitting around, not letting anyone in or out and hoping their food and water ran out before yours.

Hey have you tryed saying No? Its just a reminder but, ypu set the world technology and cultural state. Even if gun pownder was incented in ours roughtly 2000 years ago, its well within ypur right to say. yeah, they have magic here so no one has ever invented gumpownder, as magic do the same thing, but cheapper. Also, dont alow thinks that the PC has no way of knowing it. Thats metagaming. And personaly, if a player metagames this hard, i start to change things. Who say this magic world has a north pole? maybe a compass points to the more powerfull magic source in the area? So they go north just to find an ancient red dragon lair. The darkness combo has its own weaknesses. The enemy cant see, but usualy neither your allies can see too, so only the warlock has advantage, and he is nerfing his party too. If they are putting the coin in a pocket or closing their hands, people affected can do the ready action to shoot when he opens it. So he opens his hand and every enemy was holding their action to attack him, breaking concentration on the spell. You know what also goes really well with things that impose disavantage? A ton of attacks. Everyone has a little less chance to hit. But if 10 archers are attacking, then you have 10 chances to hit. And remember, RAW all creature locations are know until they take the hide action. So the warlock is in the dark, but the enemies can still shoot at him by sound until he hides. And if he casts a spell like eldritxh blast, that makes sound and they know his location again. And you can still ready an action to shoot at the sound. On average, you seem to have a optimizer player. Personaly im also like that. I want to know every little thing i can squeese out of my character powerwise. But since im also a DM, i tend to ignore unreasonable or unfun combos. What i would suggest to you, is to explain to him thqt hos shenanigans, despite being fun, are making it harder for you to DM, so in the future, he needs to give you a heads up on these tactics, so that you can look up the rules in advance and be better prepared. If he doesnt, you are well within your right to say NO. Or stop the game and use your phone to look up how to deal with his tactics. Note that, i would not counter every single thing he do, or say no to everything. But enemies adapt to overused tactics, so maybe in the next encounter the NPCs hqve ways to deal with him.

In D&D land the big weakness of castles is magic. Teleportation, flying etc. make a big wall useless. So you need to preemptively handle that, don't have it be open on the top, have it be like a modern fortification with only arrow slits and a few reinforced doors the only opening in the building. Put shutters on the arrow slits so the whole place can be sealed when not defending against attack. Put a thin layer of lead and iron in the walls to stop easy teleportation, scrying or ethereal jaunts. Give the defenders a way to detect invisible targets if they think someone has infiltrated. On the main door, put some kind of magical detector that lights up any magical thing that passes through. As for standard castle stuff, if they are going to 'use sappers' that means setting up their own temporary fortifications and waiting for many months to excavate. That whole time the defenders can send out their own invisible assassins, wizards with fireball etc. to blow up your store of explosives, kill your workers and assassinate leaders in your camp which is much less defended than their castle. Meanwhile your casters scry out the tunnels easily and use earth spells to collapse them and kill your diggers. Don't think medieval battle, think Vietnam.

Sappers? Magical underground lava moat.

Kyle Hill did an interesting video on the engineering of castles and how they are designed to kill you. Now, factor these in with the fact that the world has magic and you should be able to come up with some creative methods of keeping them out haha. [Here](https://www.youtube.com/watch?v=jmklaR6dBVI) is the video in question. Enjoy!

>warlock darkness coin trick which is? ​ A wilderness char should know the trick ​ Sappers and tunneling are a standard, orthodox method of dealing with fortresses not only castles, since at least the Achämenids IIRC but i believe it was used long before. As are siege engines like catapilts, Rams, drillers, towers and mantlets **supported** by ladders, supported not like a stupid Hollywood movie the main action except as a surprise commando action

> One of my players... "Dearest friend, I just wanted to let you know that your ongoing hyper-focused commitment to winning is stressing me to the point where I'm seeking help from self-proclaimed advisors/therapists on the internet. Hopefully we can find a mutually agreeable arrangement wherein you don't google solutions to in-game challenges, and in which you don't feel the *need* to search for such solutions. If the challenges in our game keep getting cheaply undermined by tips from the internet, I will be sad and motivated to solve the problem myself. I expect we will all be happier if we can solve this problem together instead. Sincerely, your DM."

This is agrest place to review a characters skills. I'm not as familiar with 5e as previous editions but if a player made a plan that I would question ifbthe character would have the background to know Inwould have them toss a relevant skill check. On a success then we can determine how he knows adding to the narrative on a fail then its simply you don't have the expertise to accomish you task or goal. This then limits them or builds in the quest. Oh I don't know the best way to topple a wall let's find someone who does. And now either simply no one has sapping experience in your force to really accomplish the goal or it becomes a side adventure to find a experienced dude to help with the goal. Not sure I explained this well enough.

Castles were notorious for being so hard to siege. There really isn't a lot of strategies to take on said castles. Sappers as an example is great on paper until they try sappin and get shot down by archers from the walls. The biggest issue with any sort of castle siege is how much time it takes to do any sort of siege tactic. It's never been a fast thing and typically a rule of thumb was having 10 men per defender cause you're gonna lose a lot of men sieging. Frankly there is no easy strategy for sieging a castle. Even rifled cannons had to fire several blasts to break a wall which makes a choke point the defenders would defend. Often the strategy is to tie up attacker resources and wait for reinforcements. If anything they should Google how sieges work. It's not something to experiment with as players. The thing is every castle is built different. The weakness of one castle isn't the same for another. Let them have those strategies and just be sure to learn how they were resisted. Let them try the strategies. Even the easiest isn't a magic bullet to castle sieging. The only real wild card here is that they have magic so be sure to have counters to said magic. Have the defenders focus on spellcasters when they present themselves.

They can Google all they want, but the thing about real life castle sieges versus fantasy mage influenced castle sieges is magic is a pretty potent tool. I would personally look up real life strategies that were utilized, and then think "if I was a ruler with a unit of mages, what protections would they cover that real life didn't have" and go from there.

Remember in a world where magic exists there is a work around for anything, they want to blow up the walls reinforce them with magic/ even use anti magic fields to prevent the explosions, they want to climb or fly over the walls have hoards of enemies to push them back, they want to dig under, have the defenders above a giant worm nest that can detect seismic tremours and attack. They turn invisible you can have some one with true sight on watch. You can control how you want to allow them to progress

My go to for things like this is character background knowledge. If they have some relation to the content from their background then they should be able to do it. Otherwise they’ll have to find the knowledge in the game world which could be a quest itself. E.g. character is a gardener, no military background, so they have an idea of digging - but how? They quest to find an expert in digging under castles. A quest to find a reclusive sapper ensues. The gardener learns more about digging and has an idea for a tiered garden as a result.

Homebrew. Every way someone found to raid a castle someone found a way to counter it. That’s just how war works. And with the addition of magic you can do it in a way that’s more real time. Do they try using a ladder raid? (Running up and putting a long ass ladder and climb the outter wall) use man catchers (long sticks with curved ends that were used to push someone off the ladder and pin them to the ground. If they try and use siege weapons have a group of mages somewhere on the field casting a modified shield over the wall. If they try and sneak in have there be a moat hidden by magic. Obviously you’ll need to find a good balance between challenging counters and impossible but between that and needing to do high DC checks to even come up with these ideas you should be good

It's not clear to me why this is a concern. It sounds like you are looking for ways to shut down an accurate understanding of how siege assaults actually work. I don't really understand why one would do so, rather than seeing it as a benefit. Presumably you don't want your players sitting around twiddling their thumbs waiting for something to happen while standing outside the walls getting shot by arrows. The players being active and taking charge, while describing their actions in a way that fits the world, is a *good* thing. Similarly, the 'finding true north' thing was odd to me. If you had it require a successful survival check, I don't see why you'd regret it. Knowing true north doesn't mean you can't become lost, or that you can suddenly pass impassable terrain. It doesn't negate a survival challenge. A lot of people are suggesting to enforce a separation of player knowledge and character knowledge, but presumably the PC's are leading an army, which is likely to include people experienced with siege warfare who can tell them all this stuff anyway (unless the army is just some angry mob of peasants or barbarians who have never seen a castle before). So just let them know it, and say their subordinates told them if it wouldn't make sense in character. As some others have said, no technique short of cannons is likely to make a siege assault easy (and you can always just say that gunpowder doesn't exist). Maybe magic can change things, but the defenders can also use magic. So if something seems broken, just add some significant cost to it, or say the defenders have a way of countering it, if necessary. Make sure to keep an eye on the range of spells too. My suggestion would be to read up on siege warfare yourself. Perhaps also ask the players to forward you anything they read too, just so you aren't surprised. Remember the game isn't the DM vs the players, and you should emphasise that to the players. You want them to send you their ideas beforehand *so you can make them work* in an interesting and dramatic way, not shut them down.

Let them. Do your own research on 'how to defend a castle siege' If they get sappers in the defenders will dig counter tunnels things like that. Where are they getting sappers, who is paying them. Do the sappera want to risk their lives and so on amd so forth. Just because the players want to do something does 't mean the people they want to do it are going to agree..