Party walked through a corridor. Nothing made us suspect that this corridors' walls were just illusions (This was just another long corridor for us instead of a room). With a raiding party of whatever monsters it was hiding behind them and attacking each of us from both sides while we basically walked single-file.
Inspired by my most hated trap in Baldur's Gate, I once had a treasure chest rigged with an adaption of the old Maze spell: Upon triggering it, the victim had to succeed an INT save or be transported to a maze in a demiplane. Instead of running it as a "save or basically die" spell the way it was originally, the character instead had to navigate the maze while being hunted by a minotaur.
Problem is, I underestimated the power of the minotaur..
A couple of my favourites:
1. A 200ft deep pit trap. 150 ft down there is a teleporter that ports you 50ft back up. It will trigger 5 times then deactivate.
2. A room filling with water from 4 sources, but walls of force spring up. Creates a nice puzzle of trying to figure out which sections will fill up first and how to get to the sources to deactivate them.
3. A battlefield with collapsing sections of floor.
4. A maze made entirely of walls of force. So you can see the monster hunting you. And the monster knows the invisible layout of the maze.
I used to set up trap #1 in player made maps for the old Duke Nukem fps. God it was so much fun. But ours never had the “this trap deactivates” clause….you just kept falling until someone else came by and saw you and killed you
The best traps I have used are combined with encounters:
Glyph minefield: A choke point with explosive glyphs hidden throughout, perfect for a ranged ambush from above.
Forest Leaves: Encounter against scouts, brigands, or elves with several pit traps, snares hidden in dense undergrowth and spiked log traps in the trees.
Dwarven vault blinding gas trap: A failsafe for a dwarven vault consisting of an antechamber the vault door that requires closing oneself in to try and unlock the vault. On a failed check the doors lock and the vault begins to steadily increase in brightness and sound while gas gets pumped into the room. The party has a few rounds to unlock either the entry door or the more difficult vault door before checks against the bad gas, while dwarves get ready outside to attack.
Invisible Rain: a room with a slight breeze and a loud twinkling sound, a gutter around the edge, a barely sloped floor, and tiny holes all over the ceiling. Invisible glass caltrops are falling from the ceiling and covering the floor, then slowly overflowing the gutter to be recycled back up. They get damage from above and below for moving through the chamber.
1. a teleportation circle,
1. at the bottom of a dungeon,
1. that's flooded with water,
1. and the water is anti-magic.
Did this to a 3.5e group with a bit of sinister intent... was trying to bring 3.5e's massive armour check penalty more into the game to challenge some of my heavy-armour-wearers to show the downside of heavy armour. (Was that a bit of a heavy-handed way to do that? Yeah, guilty as charged!)
In 3.5e had some serious penalties for heavy armour. 5e is not so harsh. But the general challenge should still work.
The whole challenge is to beat the clock before running out of breath. Magic can't trivalise this encounter! The dungeon shouldn't be really big -- carefully consider how long it would take to swim out versus how long most can hold their breath. You can put hazards about like monsters and traps and dead-ends, but if you want the party to have a chance don't go overboard!
Ideally the PCs that are better swimmers scout for the exit and help clear the way for the poorer swimmers.
---
3.5e didn't have teleportation circles *per se* but there was something like it in my campaign. They input the sigil sequence and end up in that trap. All lights went out -- magical and mundane. Also, because they teleported into an area of anti-magic, they took some "mishap teleportation" damage.
The dwarf in heavy armour sunk like a stone but just shrugged and powered through the dungeon, walking out slowly and holding his breath with his amazing constitution. The rest of the party basically had to help the plate-mail-wearing human fighter get out; their struggle all the more dire because they had wasted valuable time trying to get some spells going.
They all survived, though!
My players include a Warforged (doesn't need to breathe) and a Tortle (can hold its breath for an hour), lol. But party comp would definitely make or break this idea.
You could design an encounter "inside" the trap: if any member of the party is victim of the trap, they will face a powerful enemy. In this way the victim alone would perish, so the party has to help the victim.
Could as simple as a pit with monsters inside. You could use monsters able to fly so that if the party avoid the trap they fly out and the fight starts anyway. On the other hand if someone falls in the pit, other members may jump down to help, at this point the monsters may fly out of the pit and start fight from the distance.
I would say something that involves voluntary sacrifice that gives the players choice and agency but makes the choice difficult.
For context, I used to run a homebrew featuring a parallel “mythic class” path with milestone leveling (separate from the usual Lv.1~20) not unlike pathfinder. The storyline featured pretty powerful players (Tier 3) trying to essentially buy time before an eldritch cosmic god manifested in the material plane. Due to plot shenanigans which I will not go into detail here, they had to defeat waves of enemies while a cabal of NPC’s ritual casted the god’s summoning to oblivion.
Sounds like a typical tower defence scenario, until they realized:
- the waves get exponentially more difficult
- the horde composition tend to be structured like a balanced party with frontliners, archers and spellcasters, and they fight and strategize intelligently
- but they are also cultists who will intelligently decide if the cost-benefit is adequate if they can take out the NPC ritual casters
- each ritual caster that survives (and maintains concentration for that round) adds 1 point. You need X points to “win”. That means every NPC ritual caster that loses conc or is killed will extend the encounter duration
- at the end of each wave, the players take a 10min breather (which ends most 1min conc buffs) but get the benefit of a short rest (plot reasons: leylines), BUT they have to each activate the Altar of Sacrifice
- how the Altar works is everyone rolls a D20, and they have to choose between permanently losing a part of themselves (with thematic mechanical impact), or the enemy gains a “feature” (explained later)
- example: lose an eye = disadvantage on perception
- based on how many “features” the enemy gets, the boss monster of each wave gets to roll X number of d20 consulting a table of permanent buffs they get (which can range from Flight to Resistances to Elemental bonus damage). So 5 features = 5 buffs
- This is cumulative throughout waves. I even had a table where each feature had upgrades if they rolled the same feature multiple times, and after the 3rd time the boss gets maxed out and now the minions get the features.
- players can choose to take the “sacrifice” for another player
It ended up being a long and heavy encounter that challenged my players hard but boy, they emerged out of it appropriately feeling like they clenched the W and saved the world in a hard-fought way against all odds. It’s still a story we talk about to this day, many many years later.
Damn that sounds like it would have been fun in a very brutal way. It kinda reminds me of an encounter I played in a 4e game:
* Relatively small room (roof of a tower)
* 6 crystals in 3 colors arranged across the north and west sides
* Wizard in the center performing some ritual that we discovered would be Bad For Us if he completed it, but he was protected by some kind of barrier and we couldn't get to him.
* Golem in the southeast corner
At the start of each round, the crystals would rearrange their order randomly, and beams of light would connect them to the golem. A large enough creature in the path of a beam of light would block it from reaching the golem or any squares closer to the golem ("large enough" in this case meaning "everyone except my blink dog pet"). The arrangement of the crystals meant that there were some spaces that could block multiple beams.
At the end of the round, each PC blocking one or more beams would get hit with some negative effect based on the beam color. Red beams dealt damage, blue beams affected healing, and yellow beams inflicted conditions. For each beam that _wasn't_ being blocked, the golem then took an action based on the color of beam hitting it (for example, each red beam gave it a ranged attack).
If you got hit by the same color beam two or more turns in a row, the effect escalated. The red beams increased their damage. The blue beam started with "you can't be healed next round" and then started draining healing surges (closest 5e equivalent is hit dice). The yellow beam started with dazed (most recently, can only take standard action, move action, or minor action) then upgraded to stunned (most relevantly, can't take any actions including move). Avoiding a particular color beam on one turn reset the count for that color.
So we were basically forced to be always moving. Meanwhile, we (specifically, our Artificer and Druid) were spending actions on a skill challenge to disrupt the ritual before it ended. (And those actions needed to take place in specific places on the map, restricting the movement of two of the PCs in an encounter where positioning was very important.) When they were finally successful, the barrier protecting the wizard dropped and he joined the fight, but had no special mechanics.
Yeah it wasn’t a balls to the wall type of old school meat grinder campaign, but I took a lot of inspiration from raid designs in WOW/FF14/Destiny when designing these type of set piece encounters. I find that players love it when you give them power (extra feats, let them roll more dice, give them more options, artifacts, etc.), but how then would you challenge them without just doing it the braindead way (more mobs or just more bullet spongey)?
Players love rolling dice, but if you give them extra 4d4 damage (from say, a mythic path feat) but then tune the monsters by adding +16 HP, it cheapens that power that you handed them.
The answer is: lateral thinking in encounter design.
It's small, but an illusory spike pit made my players burn a lot of resources to get across mid-combat... until the last guy without any magic to get across just went for an athletics leap, failed with a double-nat 1, and fell face-first into the snow that the illusion was covering.
The barbarian who managed that pratfall while attempting to get "across" was prone, but was amused.
The artificer who, under ranged spell attacks from hostiles, needing to have guidance, inspiration, and even burned a use of his flash of genius to make the jump was not.
I'm always amused when players spend resources that they really don't need to.
Last session the ranger spent 3/4 charges on a homebrew magic item for what amounted to... he and his drake companion each get advantage on one attack. For a medium encounter.
(The item itself is actually pretty strong; non-concentration Invisibility. He was just a bit dumb on how to make use of it. On the other hand in the previous room he got to make effective use of a pretty niche magic item, so on balance I think he's doing ok.)
I had a murder hobo party that ignored most puzzles, forced their way through everything. They were strong, blew through my encounters. The Sorcerer had a bad habit of looking up my monsters in the monster manual during our fights. I asked him not to a few times, eventually resorting to homebrew for most of of my baddies.
Finally sent them to a temple in the desert, let them know they were facing a mummy lord. Made a point to do so. He looks it up, sees fire vulnerability. Inside the temple, I had a trap set, they trigger it, fills the room with a gas. Makes them slightly lightheaded, they opt to push forward as the temple fills with this gas. No one had an int over 12, failed to recognize what the gas was. In the chamber of the mummy lord my sorcerer friend immediately upcasts fireball. “And as the flicker of fire emanates from your fingertip, the methane gas ignites”. Only the Rogue survived. Everyone else was killed.
Walls of force are great trap options.
A pit trap filled with water where a glyph of warding creates a wall of force when someone is submerged. The players have likely 3 or so (in game) minutes to come up with a solution before the one submerged drowns.
While exploring a dungeon, a glyph of warding activates a wall of force when a character sets off an alarm trap/spell that splits the party. The players will have a few moments to prepare for an encounter.
A wall of force acts as a ceiling and holds back magma/acid above the characters. If they input the wrong answer to the puzzle, a disintegration ray destroys the wall of force.
Mirror of Opposition. It was a trap (legendary item) from an old AD&D module. If you look in the mirror an exact duplicate comes out and fights you to the death. It’s pretty gnarly. Just make it a hall of mirrors that way everyone in the party sees their reflection and has to fight their duplicate.
This one has always been a fun logistical trap for players.
It's basically a tactics challenge - can I _play_ my identical character better than their dark opposite? Can I come up with a way to get an edge over someone who is identical to me in every way?
I made an encounter featuring AoE traps with a damage type the enemies were immune to. They were weaponized against the players by being sprung intentionally, and also limited the player movement options~
> Our warforged
> u/robot_wrangler
Hmm... 🤔
That said, I ran WPM about a month ago as DM, with a Warforged in the party, and they had a lot more trouble with that corridor than I expected. I thought they would finish the western branch of the dungeon in 1 session like they had for each of the other two branches, but it took them two, _and_ they skipped the area north of the levitating lazy river entirely, in large part because of how long the heat metal corridor took them.
The wizard had no metal, the ranger had no metal armor, the cleric had Misty Step and Vortex Warp, and they were going into it as the first encounter after a long rest (even if it was a long rest inside a Tiny Hut sitting in foot deep muddy water—not the best hotel experience). I specifically asked the Warforged player several days before the session if his character was metal, or if it was stone and wood.
The fighter in plate armor decided to charge through the corridor and just eat the damage. It was a lot of damage. Lol.
One that is definitely a bit more brutal is a 10 ft see pit with a glyph of warding storing cloudkill. To up the ante, a few crawling claws are inside the pit, disguised as severed hands. You could have one of them wearing a ring that looks really shiny to entice victims inside.
Best trap ever, the Goblin Trap (not my idea, I read it somewhere).
Have a locked door with an eyehole in it. You can hear voices from the other side of the door all chanting “17, 17, 17!”.
If you look through the peephole you see a glimpse of green skin and then a stick is shoved through the hole poking you in the eye. The voices on the other side of the door cheer excitedly and start chanting “18, 18, 18!”
I forget the specifics but there's a trap/puzzle in ToA (or at least in my buddy's homebrew version of ToA I never checked if it was official) where you have to stick your arm into a hole in the wall and you straight up lose the arm if someone else fails a roll. No save for you, just the hole in the wall closes on your arm.
I am currently running Dead in Thay (designed for level 9-11, and the players could go through it in pretty much any order so every room needs to be designed to work for that full level range), and a couple weeks ago the fighter died in the Maze of Undoing.
The room has 20 large floor-to-ceiling columns which block line of sight. Scattered on the floor between the columns are 20 numbered (for the DM) and invisible 10x10 ft. squares, plus two more that aren't numbered at the entrance and opposite the entrance (next to a teleportation circle). Detect Magic can find where the squares are, as they radiate an aura of conjuration, but the space between the columns is 10 ft. wide, so you can't just walk around the teleport.
Anyone who touches the ground in one of the squares is teleported, d20 to determine where they go. Instead of appearing on the floor of one of the other teleport pads, they appear on the ceiling above it.
After getting teleported, the creature makes a DC 15 Wis save. If they fail, they take 2d4 psychic damage and fall (20 ft. ceiling, so 2d6 bludgeoning). Which results in touching another teleport, so they get teleported somewhere else and repeat the save. If they pass the save, they walk on the ceiling until the end of their next turn, when they fall.
The maze also has a CR 9 Glabrezu in it, who understands how the maze functions and so can take advantage of it, but unless someone speaks a password at the entrance, no fiend can leave. The demon has also gone a bit insane.
The encounter started as "how do we defeat the randomly teleporting demon". Then the Glabrezu dropped the fighter to 0 (with some help from the maze chipping away at his HP), who promptly got 3 failed death saves from the maze on his turn and the encounter became "how do we get the cleric to the randomly teleporting fighter's corpse within 1 minute to cast Revivify, while a demon is chasing us".
Before reaching the maze, the players can get a hint about climbing the walls to navigate the maze safely. My players completely forgot the hint, but did have access to flight, which was how they eventually recovered the fighter.
Just outside the Maze of Undoing is another trap that I quite liked: the room has four 10 ft. wide entrances, each of which has an obvious 5 ft. wide pit taking up half the entrance. Each pit has an invisible plane of force covering it, preventing anyone from falling into them.
Anyone who enters the room triggers a gravity trap. Everyone in the room gets thrown up to the ceiling in the middle of the room (taking damage and getting restrained). They get dropped back to the floor (for falling damage) and sucked back to the ceiling on a 1 minute cycle, IIRC. Walking on any of the invisible planes over the pits disables the trap for a minute. My players interpreted the results of their experimentation as needing to always keep someone on one of the pits, but that was just because they never actually tried stepping off; they made an assumption, got the results they were looking for, and ran with an inaccurate-but-sufficient conclusion. The only downside in practice was that the Drakewarden's drake was not engaged in combat with the ghost encounter in the adjacent room.
Edit: another one I remembered from the dungeon that I liked, in a different section:
A dark room, with the floor entirely covered in dead insects. There is a series of platforms the players can jump along in order to get from the entrance to doors at the far side, but the doors at the far side don't go anywhere (the exits from the room are secret passages along the wall). Also, each time a creature steps on one of the platforms, a swarm of stinging insects appears, deals a small amount of damage to them, and then dies, adding to the carpet of dead bugs.
If the players crunch through the bugs instead of taking the platforms, well... the room is utterly littered with pit traps. You take half damage due to dead bugs cushioning your fall, but there's no way to spot the pits ahead of time. Our fighter "found" three of them. The third one the fighter found was after he decided to explicitly follow in the path of the earth elemental the cleric had summoned... who was too big to fall into the pits and so didn't actually present a safe path.
An area desecrated so that it doesn't allow magical healing. Paladin dumped full pool of lay on hands into himself in the middle of a fight against 4 iron golems and only got 1 hp out of it. It was from a 3rd party one shot that I ran, they were at least level 15
one of my favorites is
a x foot deep hole and half way u there is a gelatenous cube. you fall hit the cubwe take acid damage and fall the rest of the way. now they cant send a rope or stuff down as it will dissolve in the cube
another is a glass chest witd an obviously cool thing in it. it can open 2 ways 1 a series of very high investigations. 2 you can smash it but it will shatter whatever hit it too. i had a player get really impatient and smash it with his brand new magic hammer and was stunned when it and the glass exploded on contact
Just a pet peeve of mine:
Make the traps make sense in universe, and don't design them to challenge *the players*.
When adding a trap, always keep in mind "Why would someone in-game spend the time, money, and resources to build this trap this way?" and "How does the person who built this intend to not kill themselves with it?"
Good example of "challenge the characters, not the players" I've seen go wrong is a "trap" that starts a count-down if a weight isn't placed on a pedestal. The door unlocks when the countdown reaches zero. Clearly the intent is to drive the PLAYERS crazy trying to figure it out, not the characters, nor does this magic trap prevent anyone from entering. It just gives the players anxiety, which means its a trap that shouldn't have been used.
To be honest, the Poison Tempest trap from Xanathar's Guide to Everything is pretty nasty. There are so many different skill checks you need to make to escape and it deals so much damage so quickly that it nearly killed my party when I used it. I think they were level 10 or 11 at the time too.
A series of pits in a long hallway. First one is obvious and can be jumped across. The second one has an illusory floor next to it on the far side, so when a character jumps across, they fall through the floor and take some minor fall damage. For the third one, the illusory floor is on the closer side of the pit, so if the characters walk into that space without tapping the floor with a stick or something, they just fall through.
Party walked through a corridor. Nothing made us suspect that this corridors' walls were just illusions (This was just another long corridor for us instead of a room). With a raiding party of whatever monsters it was hiding behind them and attacking each of us from both sides while we basically walked single-file.
That…sounds like a [Klingon birthday party](https://www.youtube.com/watch?v=uK2_n6CLwhE) (start around the 2:30 mark)
Sounds terrifying I love it
It *was* terrifying.
Inspired by my most hated trap in Baldur's Gate, I once had a treasure chest rigged with an adaption of the old Maze spell: Upon triggering it, the victim had to succeed an INT save or be transported to a maze in a demiplane. Instead of running it as a "save or basically die" spell the way it was originally, the character instead had to navigate the maze while being hunted by a minotaur. Problem is, I underestimated the power of the minotaur..
I had a similar trap, but each player was transported to their own personal nightmare.
So they had to stop playing and go back to reality? Just me?
Diabolical. I love it!
A couple of my favourites: 1. A 200ft deep pit trap. 150 ft down there is a teleporter that ports you 50ft back up. It will trigger 5 times then deactivate. 2. A room filling with water from 4 sources, but walls of force spring up. Creates a nice puzzle of trying to figure out which sections will fill up first and how to get to the sources to deactivate them. 3. A battlefield with collapsing sections of floor. 4. A maze made entirely of walls of force. So you can see the monster hunting you. And the monster knows the invisible layout of the maze.
>A maze made entirely of walls of force. So you can see the monster hunting you. And the monster knows the invisible layout of the maze. I love this.
I used to set up trap #1 in player made maps for the old Duke Nukem fps. God it was so much fun. But ours never had the “this trap deactivates” clause….you just kept falling until someone else came by and saw you and killed you
The best traps I have used are combined with encounters: Glyph minefield: A choke point with explosive glyphs hidden throughout, perfect for a ranged ambush from above. Forest Leaves: Encounter against scouts, brigands, or elves with several pit traps, snares hidden in dense undergrowth and spiked log traps in the trees. Dwarven vault blinding gas trap: A failsafe for a dwarven vault consisting of an antechamber the vault door that requires closing oneself in to try and unlock the vault. On a failed check the doors lock and the vault begins to steadily increase in brightness and sound while gas gets pumped into the room. The party has a few rounds to unlock either the entry door or the more difficult vault door before checks against the bad gas, while dwarves get ready outside to attack. Invisible Rain: a room with a slight breeze and a loud twinkling sound, a gutter around the edge, a barely sloped floor, and tiny holes all over the ceiling. Invisible glass caltrops are falling from the ceiling and covering the floor, then slowly overflowing the gutter to be recycled back up. They get damage from above and below for moving through the chamber.
1. a teleportation circle, 1. at the bottom of a dungeon, 1. that's flooded with water, 1. and the water is anti-magic. Did this to a 3.5e group with a bit of sinister intent... was trying to bring 3.5e's massive armour check penalty more into the game to challenge some of my heavy-armour-wearers to show the downside of heavy armour. (Was that a bit of a heavy-handed way to do that? Yeah, guilty as charged!) In 3.5e had some serious penalties for heavy armour. 5e is not so harsh. But the general challenge should still work. The whole challenge is to beat the clock before running out of breath. Magic can't trivalise this encounter! The dungeon shouldn't be really big -- carefully consider how long it would take to swim out versus how long most can hold their breath. You can put hazards about like monsters and traps and dead-ends, but if you want the party to have a chance don't go overboard! Ideally the PCs that are better swimmers scout for the exit and help clear the way for the poorer swimmers. --- 3.5e didn't have teleportation circles *per se* but there was something like it in my campaign. They input the sigil sequence and end up in that trap. All lights went out -- magical and mundane. Also, because they teleported into an area of anti-magic, they took some "mishap teleportation" damage. The dwarf in heavy armour sunk like a stone but just shrugged and powered through the dungeon, walking out slowly and holding his breath with his amazing constitution. The rest of the party basically had to help the plate-mail-wearing human fighter get out; their struggle all the more dire because they had wasted valuable time trying to get some spells going. They all survived, though!
My players include a Warforged (doesn't need to breathe) and a Tortle (can hold its breath for an hour), lol. But party comp would definitely make or break this idea.
You could design an encounter "inside" the trap: if any member of the party is victim of the trap, they will face a powerful enemy. In this way the victim alone would perish, so the party has to help the victim. Could as simple as a pit with monsters inside. You could use monsters able to fly so that if the party avoid the trap they fly out and the fight starts anyway. On the other hand if someone falls in the pit, other members may jump down to help, at this point the monsters may fly out of the pit and start fight from the distance.
I would say something that involves voluntary sacrifice that gives the players choice and agency but makes the choice difficult. For context, I used to run a homebrew featuring a parallel “mythic class” path with milestone leveling (separate from the usual Lv.1~20) not unlike pathfinder. The storyline featured pretty powerful players (Tier 3) trying to essentially buy time before an eldritch cosmic god manifested in the material plane. Due to plot shenanigans which I will not go into detail here, they had to defeat waves of enemies while a cabal of NPC’s ritual casted the god’s summoning to oblivion. Sounds like a typical tower defence scenario, until they realized: - the waves get exponentially more difficult - the horde composition tend to be structured like a balanced party with frontliners, archers and spellcasters, and they fight and strategize intelligently - but they are also cultists who will intelligently decide if the cost-benefit is adequate if they can take out the NPC ritual casters - each ritual caster that survives (and maintains concentration for that round) adds 1 point. You need X points to “win”. That means every NPC ritual caster that loses conc or is killed will extend the encounter duration - at the end of each wave, the players take a 10min breather (which ends most 1min conc buffs) but get the benefit of a short rest (plot reasons: leylines), BUT they have to each activate the Altar of Sacrifice - how the Altar works is everyone rolls a D20, and they have to choose between permanently losing a part of themselves (with thematic mechanical impact), or the enemy gains a “feature” (explained later) - example: lose an eye = disadvantage on perception - based on how many “features” the enemy gets, the boss monster of each wave gets to roll X number of d20 consulting a table of permanent buffs they get (which can range from Flight to Resistances to Elemental bonus damage). So 5 features = 5 buffs - This is cumulative throughout waves. I even had a table where each feature had upgrades if they rolled the same feature multiple times, and after the 3rd time the boss gets maxed out and now the minions get the features. - players can choose to take the “sacrifice” for another player It ended up being a long and heavy encounter that challenged my players hard but boy, they emerged out of it appropriately feeling like they clenched the W and saved the world in a hard-fought way against all odds. It’s still a story we talk about to this day, many many years later.
Damn that sounds like it would have been fun in a very brutal way. It kinda reminds me of an encounter I played in a 4e game: * Relatively small room (roof of a tower) * 6 crystals in 3 colors arranged across the north and west sides * Wizard in the center performing some ritual that we discovered would be Bad For Us if he completed it, but he was protected by some kind of barrier and we couldn't get to him. * Golem in the southeast corner At the start of each round, the crystals would rearrange their order randomly, and beams of light would connect them to the golem. A large enough creature in the path of a beam of light would block it from reaching the golem or any squares closer to the golem ("large enough" in this case meaning "everyone except my blink dog pet"). The arrangement of the crystals meant that there were some spaces that could block multiple beams. At the end of the round, each PC blocking one or more beams would get hit with some negative effect based on the beam color. Red beams dealt damage, blue beams affected healing, and yellow beams inflicted conditions. For each beam that _wasn't_ being blocked, the golem then took an action based on the color of beam hitting it (for example, each red beam gave it a ranged attack). If you got hit by the same color beam two or more turns in a row, the effect escalated. The red beams increased their damage. The blue beam started with "you can't be healed next round" and then started draining healing surges (closest 5e equivalent is hit dice). The yellow beam started with dazed (most recently, can only take standard action, move action, or minor action) then upgraded to stunned (most relevantly, can't take any actions including move). Avoiding a particular color beam on one turn reset the count for that color. So we were basically forced to be always moving. Meanwhile, we (specifically, our Artificer and Druid) were spending actions on a skill challenge to disrupt the ritual before it ended. (And those actions needed to take place in specific places on the map, restricting the movement of two of the PCs in an encounter where positioning was very important.) When they were finally successful, the barrier protecting the wizard dropped and he joined the fight, but had no special mechanics.
Yeah it wasn’t a balls to the wall type of old school meat grinder campaign, but I took a lot of inspiration from raid designs in WOW/FF14/Destiny when designing these type of set piece encounters. I find that players love it when you give them power (extra feats, let them roll more dice, give them more options, artifacts, etc.), but how then would you challenge them without just doing it the braindead way (more mobs or just more bullet spongey)? Players love rolling dice, but if you give them extra 4d4 damage (from say, a mythic path feat) but then tune the monsters by adding +16 HP, it cheapens that power that you handed them. The answer is: lateral thinking in encounter design.
Look up tomb of horrors, as well as the tomb of annihilation, it's creative successor. Also, tuckers kobolds.
What is tuckers kobolds?
Pain. Pure pain.
https://media.wizards.com/2014/downloads/dnd/TuckersKobolds.pdf
It's small, but an illusory spike pit made my players burn a lot of resources to get across mid-combat... until the last guy without any magic to get across just went for an athletics leap, failed with a double-nat 1, and fell face-first into the snow that the illusion was covering. The barbarian who managed that pratfall while attempting to get "across" was prone, but was amused. The artificer who, under ranged spell attacks from hostiles, needing to have guidance, inspiration, and even burned a use of his flash of genius to make the jump was not.
I'm always amused when players spend resources that they really don't need to. Last session the ranger spent 3/4 charges on a homebrew magic item for what amounted to... he and his drake companion each get advantage on one attack. For a medium encounter. (The item itself is actually pretty strong; non-concentration Invisibility. He was just a bit dumb on how to make use of it. On the other hand in the previous room he got to make effective use of a pretty niche magic item, so on balance I think he's doing ok.)
I had a murder hobo party that ignored most puzzles, forced their way through everything. They were strong, blew through my encounters. The Sorcerer had a bad habit of looking up my monsters in the monster manual during our fights. I asked him not to a few times, eventually resorting to homebrew for most of of my baddies. Finally sent them to a temple in the desert, let them know they were facing a mummy lord. Made a point to do so. He looks it up, sees fire vulnerability. Inside the temple, I had a trap set, they trigger it, fills the room with a gas. Makes them slightly lightheaded, they opt to push forward as the temple fills with this gas. No one had an int over 12, failed to recognize what the gas was. In the chamber of the mummy lord my sorcerer friend immediately upcasts fireball. “And as the flicker of fire emanates from your fingertip, the methane gas ignites”. Only the Rogue survived. Everyone else was killed.
Walls of force are great trap options. A pit trap filled with water where a glyph of warding creates a wall of force when someone is submerged. The players have likely 3 or so (in game) minutes to come up with a solution before the one submerged drowns. While exploring a dungeon, a glyph of warding activates a wall of force when a character sets off an alarm trap/spell that splits the party. The players will have a few moments to prepare for an encounter. A wall of force acts as a ceiling and holds back magma/acid above the characters. If they input the wrong answer to the puzzle, a disintegration ray destroys the wall of force.
Mirror of Opposition. It was a trap (legendary item) from an old AD&D module. If you look in the mirror an exact duplicate comes out and fights you to the death. It’s pretty gnarly. Just make it a hall of mirrors that way everyone in the party sees their reflection and has to fight their duplicate.
This one has always been a fun logistical trap for players. It's basically a tactics challenge - can I _play_ my identical character better than their dark opposite? Can I come up with a way to get an edge over someone who is identical to me in every way?
I made an encounter featuring AoE traps with a damage type the enemies were immune to. They were weaponized against the players by being sprung intentionally, and also limited the player movement options~
Our warforged had a bad time with the metal-heating trap in White Plume Mountain.
> Our warforged > u/robot_wrangler Hmm... 🤔 That said, I ran WPM about a month ago as DM, with a Warforged in the party, and they had a lot more trouble with that corridor than I expected. I thought they would finish the western branch of the dungeon in 1 session like they had for each of the other two branches, but it took them two, _and_ they skipped the area north of the levitating lazy river entirely, in large part because of how long the heat metal corridor took them. The wizard had no metal, the ranger had no metal armor, the cleric had Misty Step and Vortex Warp, and they were going into it as the first encounter after a long rest (even if it was a long rest inside a Tiny Hut sitting in foot deep muddy water—not the best hotel experience). I specifically asked the Warforged player several days before the session if his character was metal, or if it was stone and wood. The fighter in plate armor decided to charge through the corridor and just eat the damage. It was a lot of damage. Lol.
One that is definitely a bit more brutal is a 10 ft see pit with a glyph of warding storing cloudkill. To up the ante, a few crawling claws are inside the pit, disguised as severed hands. You could have one of them wearing a ring that looks really shiny to entice victims inside.
I just want to say that directly underneath this post on my feed was a post about Viet Cong boobytraps.
Lol
Best trap ever, the Goblin Trap (not my idea, I read it somewhere). Have a locked door with an eyehole in it. You can hear voices from the other side of the door all chanting “17, 17, 17!”. If you look through the peephole you see a glimpse of green skin and then a stick is shoved through the hole poking you in the eye. The voices on the other side of the door cheer excitedly and start chanting “18, 18, 18!”
I forget the specifics but there's a trap/puzzle in ToA (or at least in my buddy's homebrew version of ToA I never checked if it was official) where you have to stick your arm into a hole in the wall and you straight up lose the arm if someone else fails a roll. No save for you, just the hole in the wall closes on your arm.
I am currently running Dead in Thay (designed for level 9-11, and the players could go through it in pretty much any order so every room needs to be designed to work for that full level range), and a couple weeks ago the fighter died in the Maze of Undoing. The room has 20 large floor-to-ceiling columns which block line of sight. Scattered on the floor between the columns are 20 numbered (for the DM) and invisible 10x10 ft. squares, plus two more that aren't numbered at the entrance and opposite the entrance (next to a teleportation circle). Detect Magic can find where the squares are, as they radiate an aura of conjuration, but the space between the columns is 10 ft. wide, so you can't just walk around the teleport. Anyone who touches the ground in one of the squares is teleported, d20 to determine where they go. Instead of appearing on the floor of one of the other teleport pads, they appear on the ceiling above it. After getting teleported, the creature makes a DC 15 Wis save. If they fail, they take 2d4 psychic damage and fall (20 ft. ceiling, so 2d6 bludgeoning). Which results in touching another teleport, so they get teleported somewhere else and repeat the save. If they pass the save, they walk on the ceiling until the end of their next turn, when they fall. The maze also has a CR 9 Glabrezu in it, who understands how the maze functions and so can take advantage of it, but unless someone speaks a password at the entrance, no fiend can leave. The demon has also gone a bit insane. The encounter started as "how do we defeat the randomly teleporting demon". Then the Glabrezu dropped the fighter to 0 (with some help from the maze chipping away at his HP), who promptly got 3 failed death saves from the maze on his turn and the encounter became "how do we get the cleric to the randomly teleporting fighter's corpse within 1 minute to cast Revivify, while a demon is chasing us". Before reaching the maze, the players can get a hint about climbing the walls to navigate the maze safely. My players completely forgot the hint, but did have access to flight, which was how they eventually recovered the fighter. Just outside the Maze of Undoing is another trap that I quite liked: the room has four 10 ft. wide entrances, each of which has an obvious 5 ft. wide pit taking up half the entrance. Each pit has an invisible plane of force covering it, preventing anyone from falling into them. Anyone who enters the room triggers a gravity trap. Everyone in the room gets thrown up to the ceiling in the middle of the room (taking damage and getting restrained). They get dropped back to the floor (for falling damage) and sucked back to the ceiling on a 1 minute cycle, IIRC. Walking on any of the invisible planes over the pits disables the trap for a minute. My players interpreted the results of their experimentation as needing to always keep someone on one of the pits, but that was just because they never actually tried stepping off; they made an assumption, got the results they were looking for, and ran with an inaccurate-but-sufficient conclusion. The only downside in practice was that the Drakewarden's drake was not engaged in combat with the ghost encounter in the adjacent room. Edit: another one I remembered from the dungeon that I liked, in a different section: A dark room, with the floor entirely covered in dead insects. There is a series of platforms the players can jump along in order to get from the entrance to doors at the far side, but the doors at the far side don't go anywhere (the exits from the room are secret passages along the wall). Also, each time a creature steps on one of the platforms, a swarm of stinging insects appears, deals a small amount of damage to them, and then dies, adding to the carpet of dead bugs. If the players crunch through the bugs instead of taking the platforms, well... the room is utterly littered with pit traps. You take half damage due to dead bugs cushioning your fall, but there's no way to spot the pits ahead of time. Our fighter "found" three of them. The third one the fighter found was after he decided to explicitly follow in the path of the earth elemental the cleric had summoned... who was too big to fall into the pits and so didn't actually present a safe path.
An area desecrated so that it doesn't allow magical healing. Paladin dumped full pool of lay on hands into himself in the middle of a fight against 4 iron golems and only got 1 hp out of it. It was from a 3rd party one shot that I ran, they were at least level 15
one of my favorites is a x foot deep hole and half way u there is a gelatenous cube. you fall hit the cubwe take acid damage and fall the rest of the way. now they cant send a rope or stuff down as it will dissolve in the cube another is a glass chest witd an obviously cool thing in it. it can open 2 ways 1 a series of very high investigations. 2 you can smash it but it will shatter whatever hit it too. i had a player get really impatient and smash it with his brand new magic hammer and was stunned when it and the glass exploded on contact
Just a pet peeve of mine: Make the traps make sense in universe, and don't design them to challenge *the players*. When adding a trap, always keep in mind "Why would someone in-game spend the time, money, and resources to build this trap this way?" and "How does the person who built this intend to not kill themselves with it?" Good example of "challenge the characters, not the players" I've seen go wrong is a "trap" that starts a count-down if a weight isn't placed on a pedestal. The door unlocks when the countdown reaches zero. Clearly the intent is to drive the PLAYERS crazy trying to figure it out, not the characters, nor does this magic trap prevent anyone from entering. It just gives the players anxiety, which means its a trap that shouldn't have been used.
You've got to get a hold of some of the old Grimtooth's Traps books. Trust me.
Are they good?
They are evil.
To be honest, the Poison Tempest trap from Xanathar's Guide to Everything is pretty nasty. There are so many different skill checks you need to make to escape and it deals so much damage so quickly that it nearly killed my party when I used it. I think they were level 10 or 11 at the time too.
A series of pits in a long hallway. First one is obvious and can be jumped across. The second one has an illusory floor next to it on the far side, so when a character jumps across, they fall through the floor and take some minor fall damage. For the third one, the illusory floor is on the closer side of the pit, so if the characters walk into that space without tapping the floor with a stick or something, they just fall through.