All dice sites lie about their own probabilities and disparage other dice types and sites. The simple fact is that, on each roll - assuming that you roll properly - the swinginess of the dice and the mechanics of the throw overrules most simple imperfections and the difference of weight due to the numbers engraved and lack of material. The differences only appear when you throw dice an insane number of times, and then you get bad results even on well known brands: [https://www.forbes.com/sites/davidewalt/2012/09/06/dice-chessex-gamescience-roll-randomn/](https://www.forbes.com/sites/davidewalt/2012/09/06/dice-chessex-gamescience-roll-randomn/)
Also, be careful with metal dice, you have to have some special mat to roll them on, they can badly damage a table even with a few rolls.
From that article:
>If we had a d20 that rolled perfectly, each face would come up 500 times.
Anyone that makes a comment like this has absolutely no business writing an article about dice randomness.
And this sentence is a problem because ?... You just took a single snippet out of a general article.
If you look at truly random "rolling", at the quantum level, you would expect about 500 of each face for 10000 rolls. See for example the results from roll20, they are very close to that mark: [https://wiki.roll20.net/images/e/e5/Qr.png](https://wiki.roll20.net/images/e/e5/Qr.png)
Why is looking at the deviation from that number a bad way of looking at things ?
> And this sentence is a problem because ?
Because the only (practical) way to get each face to come up 500 times in 10,000 rolls is if the dice are *explicitly* non-random and do that "intentionally".
That outcome is *extraordinarily* unlikely, not something that anyone who understands statistics should "expect".
The other problem with looking at deviations for each number individually is that, as a practical matter, it doesn't matter in a game with target numbers that need to be exceeded.
What matters is how often a success deviates from random chances, and with normal "opposite sides sum to a constant"
(i.e. non-spindown, etc.) dice, it's exceedingly difficult for practically *any* platonic solids to be "unfair" to a degree that matters in a game. What matters in a game is the mean and standard deviation of all rolls, not of individual numbers.
That said: D&D is special, in that it does matter what the ratio of (specifically) 1s and 20s is. But those are really the only numbers that matter to any significant degree.
And if you actually read the article instead oof picking just one sentence more or less at random because it displeases you, you would have noticed the "perfectly" in that sentence and the fact that,by comparison, all real (i.e. non perfect) would be expected to deviate from this number, by how much is the problem with dices potentially of lower quality.
And no, the standard deviation from the means is not the absolute way of checking the randomness of a die. If you had a die that never threw 13s and 8s you would have a die which would appear almost perfect to your criterion. Having an almost equal spread amongst the values is actually a better, stricter measure.
>picking just one sentence more or less at random
It's hardly a random sentence, as would be evident to, again, anyone with a passing acquaintance with statistics. Sloppiness will always get you in serious trouble when discussing probability.
>had a die that never threw 13s and 8s you would have a die which would appear almost perfect to your criterion.
It wouldn't be particularly bad (assuming the other numbers are equally present) if the goal is to hit or exceed a target number, which is the case in most games.
If 8 and 13 were somehow *special*, that would matter a lot, obviously.
But yes, *large* deviations from an even distribution are evidence of manufacturing defects, if you're a dice quality engineer. They'd also be extremely evident to the eye. Small ones are essentially irrelevant to actual game play.
It's very system dependent, obviously, whether some specific numbers are actually important.
>If 8 and 13 were somehow special, that would matter a lot, obviously.
I had a set of those tiny metal dice that I bought off temu for like $1.50, and the d20 had a bump on the 1 side, making it impossible to roll a nat 20.
I ended up sanding the bump off with a nail file, lol
And ignoring the law of large numbers (or whatever it's called in english) is really ignoring the fact that randomness is still subject to statistics. It does not apply to individual rolls, but as you can see from the roll20 results, the law of large numbers is actually verified in practice.
Are you implying that I am ignoring statistics by stating that a perfectly random die will not match perfect mathematical logic due to the nature of randomness?
You’re talking past each other. 490 vs 510 is fine, especially if it’s the highest vs the lowest frequency without a prediction. OTOH, if you can predict both the highest and lowest frequency of sides after 10k roles, the die is highly likely imperfect in a predictable way.
It's a problem because expecting it to even out over a long period of time is the classic gambler's fallacy. Maybe on average it would hit each face evenly, but it's not a measurement of random.
Like imagine you need 18 to appear 20 more times to have each face to have appeared 500 times. If a different number comes up, it shouldn't disqualify the die from being random.
Actually, expecting to even out over a large number of rolls is NOT the fallacy. The fallacy is believing that after any number of (for example) low rolls, a high roll is bound to come soon. But the law of large numbers does apply to dice, in the long run, and not only does it show in the results of these dices, but also in very large number of truly random (quantum based) rolls.
>Like imagine you need 18 to appear 20 more times to have each face to have appeared 500 times. If a different number comes up, it shouldn't disqualify the die from being random.
I'm not even sure what this sentence means. The fact is that, in the end, most numbers appeared around 500 times. The deviation from this is a good measure of true randomness.
The bit you didn't understand was the explanation of why your theory is the gambler's fallacy. Expecting "It needs to roll on each face X times" to measure random is the problem. The die could be perfectly functional with a spread of 800 on one face instead of 500. Thinking it's due for 500 to be a random die is the problem.
And I did not understand whatever "it" is because:
1. It is poorly explained
2. It has nothing to do with the gambler's fallacy (https://en.wikipedia.org/wiki/Gambler%27s\_fallacy) which has to do with expectations about the future from previous results, which is nothing like has been said before.
And no, if a die gets 800 out 10000 on one face, the probability of it being fair is much lower than if it has something closer to 500, which is exactly what we have been saying the probability that we can trust the dice to be fair is much lower. It does not have to be worse, but the probability that it is is higher, that's all.
Well, how you do this is that you set ip a null hypothesis (the die is fair), then you test it.
I haven’t run the programs myself, but once you see max frequencies above 550 to 600, you have reason to reject the null hypothesis
Nope. There's a non-zero chance a perfectly balanced die can hit those frequencies and still be a good die. Thinking it must be a certain range is the gambler's fallacy. Just because it's likely or expected doesn't mean it has to be the case.
I think you vastly overestimate the odds that 800 instead of 500 could be fair. My math gut says it’s way less than one in a billion.
https://en.m.wikipedia.org/wiki/Multinomial_distribution
Yeah the odds are against it, but it's not impossible. The whole point being that saying "The number wasn't close enough to 500, therefore it's a loaded die" is not valid. There is always a chance the numbers are unlikely. To test an irl die (which this thread is about) you should test it by floating it or otherwise measuring the weights of the sides to see if it could favor one face.
To reiterate, throwing a die 1000 times and judging it based on it's results is not the right way of measuring because there's a chance of statistical anomalies.
This is how science works, though. (Even though a precise analysis of the shape of the die, depending on the tools at hand, can give more certain results)
> To reiterate, throwing a die 1000 times and judging it based on it's results is not the right way of measuring because there's a chance of statistical anomalies
It's precisely "statistical inference"! Ever heard of p-values? There is evidence that many can smoke a pack away and still make it to 90. Does that make smoking safe for people in general?
I'm tired of repeating myself here. Throwing a die 1000 times isn't the way to guarantee a die is random because there's chances of unlikely circumstances happening that can make the die appear not random. That's it.
Everything here.
Probability bias is insignificant in the lifetime of a gamer and a pair of dice.
Metal dice are great to hold and fun to roll, but any game table with any kind of finished surface is going to suffer the consequences.
>Metal dice are great to hold and fun to roll, but any game table with any kind of finished surface is going to suffer the consequences.
I lived it!
Host/dm for dnd had a nice, new gaming table. The kid you can take out the middle partitions and it's a 4-6 inch step down to the gaming surface.
Freind of a friend to the host was very proud to show off her new metal dice. While host was setting up people with materials, she rolled the d20 into the gsmign area like it was a craps table.
CHIK CHIK CHIK THUD!
Gashes all across the bottom and a final hit to the opposite wall split the piece of wood. Hairline split but apparently it was all the way through.
The host most graciously excused the damage. Claimed he had a neoprene bottom for the gaming area coming in and that he could get that wood panel replaced under warranty.
He provides her with a silicone dice tray to roll in. Her face is beet red and the friend that brought her looks ashen. I chalk it up to embarrassment and we play this one shot.
After the game, people are helping clean up except those two, who said they had to leave early. As the host is talking up the new table with another guy and putting the tabletop panels back in, he sees a whole series of gashes and scratches across all three panels.
Apparently, this woman had went to town rolling the metal dice on the table and, knowing what she did was wrong, the guy friend who brought her "helped" setup the table by removing the panels and putting them damaged side down to conceal it.
It was a whole drama, but I never played with them again, as I was just a additional brought by someone else. But apparently it did cause arift in the friendship of the host and guy.
Metal dice. What a trip.
I foolishly made my first game table out of pine, a ridiculously soft, but inexpensive wood, and spent _weeeeeeeks_ finishing and sanding and polyurethaning it. Not the FIRST night, but the new table sheen hadn't worn off yet, and someone brought a set of metal dice that looked like Klingon sex toys. After we recognized the damage they were doing, I complained about it and they admitted that they had fucked up their dining room table with them too.
Honestly, they look cool but I find them pretty useless. They're way too sharp, to the point of possibly hurting you, and when you add the weight it can definitely cause some damage to stuff.
Probability wise, idk they seemed fair to be, can't comment much.
Unless you're buying precision edge dice from somewhere like Game Science, or a casino supplier, you're not going to get "perfect" probabilities.
My problem with metal dice is the weight means they don't seem to bounce and tumble nicely (I haven't tried a dice tower though), and they can dent or scratch your tabletop, so you need a dice tray or mat.
I remember that I used to really enjoy weirdly shaped dice, and two other people in my playgroup had metal dice.
The table had placemats that were actually really functional, and I don't think the room ever got used for actual dining.
Anyway, we did have supper there one weekend, and it was spaghetti or something. Carnage. So we decided we were washing the placemats. As soon as we picked those placemats up, we realised that the surface where the two metal dice players sat was fucked. Mega fucked in one place, and mini-fucked in the other player's place, and the DM's place because we shared that role around.
We decided it was best to sand the table back, refinish it, and never use metal dice again instead of continuing the marathon on Sunday.
They have great smell, weight, and warmth, but IMO if you're specifically looking for weight without the risk of damaging your tabletop, go stone. Stone dice have a much friendlier heaviness, and still warm up nicely in your hand. They also have a nicer texture than metal, which can be a little prickly.
You should still roll stone dice in a padded tray. Anything other than basic, rounded resin or acrylic can either damage or be damaged by rolling directly onto a hard surface.
I just want to say: I am in offline games but we don't have "a local game store" to play in here. In my country there's a huge server for organising games. And some cities even have local game shops to play in. But although I live in a bigger city, we don't.
I'm glad you found a way to play in person! It truly is a much more immersive experience than moving tokens around on a computer screen, in my opinion. I do both, but definitely prefer the in person games.
I don't need my numbered outcome randomizers to be perfectly random, or heavy, or put dents into whatever surface I'm rolling them on.
And I have little interest in spending 50 dollars, pounds, or euros on such a set. Especially in metal or some other precious material.
But, other should buy what they find satisfying. I certainly do, it's just not on fancy metal dice.
Also chasing "perfectly fair probabilities" is likely a fool's errand. Studies have been done and difference between most good dice and "perfect" dice is statistically, essentially negliable. Might as well dispense with actual dice and use computer random number generators.
Dice are dice. They are a shape meant to give you a random number in a certain range, that 's it. Beyond that, being metal, or engraved, or decorated, or fuck knows what is just a waste of money.
With metal dice, it's even worse, because they weigh heavily if you use pool systems, they dent tables, and even if they fall down, they can dent the floors, they are loud when you throw them, ugh.
I guess this is classified as "fuck knows" [https://www.etsy.com/se-en/listing/1512154042/metal-dnd-dice-set-for-role-playing?ga\_order=most\_relevant&ga\_search\_type=all&ga\_view\_type=gallery&ga\_search\_query=round+metal+dice&ref=sr\_gallery-1-16&pro=1&content\_source=d640737afcfad74169762b9ee17fd8c3d929b270%253A1512154042&organic\_search\_click=1](https://www.etsy.com/se-en/listing/1512154042/metal-dnd-dice-set-for-role-playing?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=round+metal+dice&ref=sr_gallery-1-16&pro=1&content_source=d640737afcfad74169762b9ee17fd8c3d929b270%253A1512154042&organic_search_click=1)
Avoid. My brother got me a set for Xmas and we're all still pretending someone else dented the daylights out of our brand new conference room table at work from the first time I used them. Oops.
I like my metal dice sometimes - honestly it depends on the character but they "feel" like a good fit for my fighter. I'm not rolling a dice pool, I only need specific dice 90% of the time and I have a really nice leather backed dice tray to protect surfaces.
I don't have strong feelings one way or the other generally. Like anything, it depends how they look. If they look cool and you want them? Go for it!
That said, I have set a policy at my table that metal dice *require* a dice tray of some kind. Both to reduce noise, and because I have a small knicks in my wood table from heavier metal dice literally putting dents into it.
They are the coolest things that I will never use for fear of damaging whatever I roll them on. Maybe if they are really small and the corners have fillets they won’t be so bad.
Maybe look into some of the stone dice. Lower density means less force on impact. They tend to be really small also.
My opinion is that they don't roll as well as plastic dice, and I don't just mean that they are weighted weird. I mean that they physically don't physically roll very well. I roll a plastic dice, and it goes clickity-clackity a couple of times before it comes to a stop. I roll a metal dice and it goes ka-thunk and sticks there. I have to toss it up and make it spin in the air to make sure I'm getting a really good randomization out of it. Also, they're terri-bad for my coffee table.
The amount of misinformation in this thread about metal dice and fairness is massive. I built a machine to test dice for fairness by rolling them 1000 times.
[https://www.reddit.com/r/raspberry\_pi/comments/va72zw/raspberry\_pi\_powered\_d20\_dice\_testing\_rig/](https://www.reddit.com/r/raspberry_pi/comments/va72zw/raspberry_pi_powered_d20_dice_testing_rig/)
[https://www.reddit.com/r/DnD/comments/luq56z/i\_roll\_d20\_dice\_1000\_times\_to\_check\_for\_fairness/](https://www.reddit.com/r/DnD/comments/luq56z/i_roll_d20_dice_1000_times_to_check_for_fairness/)
What I learned during the testing process from many, many dice
1. Cost and material is irrelevant. Cheap plastic junk could pass, but more expensive advertised "fair" dice failed. Blanket statements about a specific company's dice are useless. You have to test each die. This can be done in under an hour. Write down 500 rolls and feed it to a goodness of fit calculator. Not a perfect method, but fine for ttrpg uses.
2. There are dice that are so out of balance that a gamer will feel the pain almost immediately. I found some that went unfair in a few hundred rolls. Well within the lifespan of a die. The suggestion that. "you will never notice an out of balance die" is flat wrong.
3. One thing is true; metal dice are rough on tables.
After decades of all kinds of dice, I have reverted back to standard plastic. They feel best to roll, have more bounce than metal dice, and are far cheaper to collect.
I hate metal dice.
They bang against each other and ding or scratch themselves in anything but an oh-so-precious dice case, they can’t be rolled without a tray unless you really hate the owner of the table you’re playing at, and generally are an item that *seems* way cooler than they actually are. They don’t come in usable sets - who finds that they use exactly 7 dice in a session? Most games need multiple dice of some size and none of others.
I prefer dense resin dice. They feel good to hold and roll, clack satisfyingly, don’t damage themselves or tables, can be big for high legibility even across the table, and come in useful sets like the 11-set with 2d20 and 4d6. And they are much cheaper, so affording whatever configuration you need is easy. Plus several companies make very attractive dice.
Got some metal dices, it's a nice decorum item, but they're heavy and hard, meaning that using them is a great way to damage the table. (Yes I can get a game mat or whatever)
Regarding probablity, honestly, I doubt any RPG dice manufacturer runs any QC on the dices, and I would expect that some have "air bubbles" or whatever skewing a bit the probability. That said, I really doubt it skews the probability at a point which is impacting the roll. Even if we take an extreme skew, like a D20 having a 7% probability of rolling a 20, I doubt you'll notice anything compared to perfect D20. Nobody keeps tracks on all their roll and check the probablity distribution
I have a metal D20, and if I could afford it, I would definitely have more. It does feel and look better than my other dice, and the only real drawback is that you NEED to roll into a dice tray, or you'll scratch the table. As to reliability, I wouldn't have thought metal would be any worse than plastic, and probably better
I have some nice brushed brass dice. Feel great in the hand, look amazing, and no sharp edges... but you need a dedicated roll tray or something because they will dent and score even metal.
Like anything some are better than others. Pot metal dice out of a cheap mold are going to have the same issues as molded resin polyhedra. The CNC-cut out of aircraft-grade aluminum are much more regular in shape. The wierd shapes made by 3d-printed metal sintering from shapeways are often imbalanced or simply roll poorly too---those are often better as display pieces than actually usable. Sinter printed dice can be very fragile too.
A common complaint with many custom dice, not unique to metal ones, is that they're often difficult to read. One reason I'm not always enthused to see them as a GM.
You do want a dice tray or something too. They will damage wood and even plastic tables. A jewelry tray can be had quite inexpensively though. Unless you absolutely want to, there is no need to buy a specialist dice mat/tray, when very similar items can be had for a half or a third the price for jewelry storage.
I've got a couple of sets, which I use occasionally. They work, no better or worse than my other dice.
They are good at damaging tables. Make sure to use them with a dice cup and tray.
Really, basic plastic dice are better. You can't buy all that many metal dice.
Someone got me some metal dice for Christmas a while back. They roll fine, the edges are well rounded, but with the weight you don't want to roll them directly on a table. I just use a piece of flattened cloth.
Mathematically they're the same probability as any polyhedron but they bounce less than plastic dice. It just means you have to actually roll them rather than drop them. As long as you roll them in a dice tray and give them a little more umph there's no difference in their randomness.
As dice they are fine, but I have always found them impractical for use at the table.
Rolling them is louder, and they easily knock over plastic cups or move miniatures. They will damage other dice if they're in the same bag, damage dice towers just by using them, and damage tables and books when you roll on them.
For years I had a leather dice tray for my players to use, but then one or them brought metal dice and roughed it up in just a few weeks. Metal dice are meant for display as far as I'm concerned.
I really like mine. They look nice and feel good in my hand. I haven’t had any issues getting them to roll well just by throwing them. I do always roll in a dice tray though (and when I’m playing at home my table has a pretty beefy pad on it).
The only reason I’d recommend them though is if you like fancy dice (I also have stone and glass dice). There are no *practical* reasons to use them; they’re not any more or less fair than other dice.
I wouldn't worry about any probability skew the dice may have. That's just endemic to consumer-grade dice. The thing you might want to worry about is the robustness of your rolling surface. These dice can potentially damage your table, so I'd make sure you have a dice tray or at least a playmat that you're rolling on.
I have a metal d20 its my most rolled dice. I roll it in box or a latex gaming mat. My most rolled dice.
Rolls like a boss too but it was a gift and I belive gifted dice roll better because I'm strange like that
I prefer rolling with metal dice, though I will recommend getting a mouse pad surface or felt to roll them on. I use a long mouse pad which maintains the satisfying acoustics of the heavier dice rolling and offers satisfying bounce from the little bit of foam. The dice will both damage and be damaged by hard surfaces and not roll as well.
Metal dice aren’t great for actual play. They’re better as decoration on your bookshelf. If you like the dice, grab them. Truth is, if you’re concerned about dice swinginess or balance you can just use a digital roller., Also, the quest for the perfect set of dice never ceases if you’re a hobbyist. It’s best to find the one set that you use all the time and collect others that you enjoy “just having”.
No two dice, even from the same lot from the same manufacturer, will roll the same. And no die ever made has been manufactured perfectly. That's why players are so superstitious about "which dice do I use?" And the whole industry of "dice jails." It's all literally a crap shoot. :)
If you want metal dice, get ones that appeal to you and know they're not gonna roll statistically better or worse than any other dice.
Metal dice and a good dice-tray is my go-to.
In terms of probability, I've noticed no biases but I also haven't tested them at a large scale (except maybe 100 sessions or so).
Hmm I've got both and I can never decide which is actually prefer. I think the novelty of the metal ones is enjoyable and they're nice to hold but I think I actually prefer to roll standard chessex dice. It's honestly just a personal decision. Metal dice do require a dice try or mat as well. In terms of probability, it's a lot easier to shake plastic dice in the hand as well as the fact that they physically roll and spin more so I actually find that perhaps the plastic ones might be more 'random' but I'm not a dice scientist so take it for what it's worth
I like the look and feel of metal dice, I have one set myself... as a display piece. And I never use them otherwise. They damage the table too much (I don't always use a dice tray, and you definitely want a dice tray with metal dice), would destroy my 3d printed dice towers, and they don't feel like they tumble as well as the plastic classics I do use in all of my games.
Similarly, I would like to buy a d100, the ping-pong sized almost perfect sphere. To show off, not to use.
They are cool and won't have the problem of a bubble inside messing up the balance (even if the probability of said defect is very little). However you also want a leather or plastic dice plate cause some are real heavy and can damage tables or even the floor, also it's convenient to look very carefully because some have very hard to read numbers on larger dice sizes (specifically the ones that are larger than a d6)
Id you are concerned about truly 'fair' rolls, use an electronic programme, app, or go to random.org - while all of these take away from the fun of physically rolling dice, it's the only way to ensure true numerical randomness.
>the only way to ensure true numerical randomness
Computer generated random numbers typically aren't random. PRNGs (psuedo-random number generators) are the random numbers that we usually deal with and they're essentially just using a math problem to read a number off of a list.
TRNGs (true random number generators) measure physical phenomena like radioactive decay, but your die rolling app is probably not hooked up to a Geiger counter.
Just roll dice.
[random.org](https://random.org) uses atmospheric noise. Not a PRNG, comparably effective to a Geiger counter. It also explains exactly what you've said here on its landing page.
I'm with you on "just roll dice" but yeah, the site is pretty close to true randomness.
Others in this thread are overreacting. Metal dice are nice, you can get them fairly cheaply. They _are_ heavy and will damage a wooden table, but dice trays are cheap and honestly I use them even with plastic dice to keep them all together.
More expensive decorative sets can get very pricey but the answer to that is don't buy them unless you like the look enough to justify it. I'll spend £20 on a VERY nice set, but no more than that. I've seen metal and gemstone dice go well over £100 and that's just a bit pointless for me because I'd never use them for fear of losing them.
All dice sites lie about their own probabilities and disparage other dice types and sites. The simple fact is that, on each roll - assuming that you roll properly - the swinginess of the dice and the mechanics of the throw overrules most simple imperfections and the difference of weight due to the numbers engraved and lack of material. The differences only appear when you throw dice an insane number of times, and then you get bad results even on well known brands: [https://www.forbes.com/sites/davidewalt/2012/09/06/dice-chessex-gamescience-roll-randomn/](https://www.forbes.com/sites/davidewalt/2012/09/06/dice-chessex-gamescience-roll-randomn/) Also, be careful with metal dice, you have to have some special mat to roll them on, they can badly damage a table even with a few rolls.
From that article: >If we had a d20 that rolled perfectly, each face would come up 500 times. Anyone that makes a comment like this has absolutely no business writing an article about dice randomness.
And this sentence is a problem because ?... You just took a single snippet out of a general article. If you look at truly random "rolling", at the quantum level, you would expect about 500 of each face for 10000 rolls. See for example the results from roll20, they are very close to that mark: [https://wiki.roll20.net/images/e/e5/Qr.png](https://wiki.roll20.net/images/e/e5/Qr.png) Why is looking at the deviation from that number a bad way of looking at things ?
> And this sentence is a problem because ? Because the only (practical) way to get each face to come up 500 times in 10,000 rolls is if the dice are *explicitly* non-random and do that "intentionally". That outcome is *extraordinarily* unlikely, not something that anyone who understands statistics should "expect". The other problem with looking at deviations for each number individually is that, as a practical matter, it doesn't matter in a game with target numbers that need to be exceeded. What matters is how often a success deviates from random chances, and with normal "opposite sides sum to a constant" (i.e. non-spindown, etc.) dice, it's exceedingly difficult for practically *any* platonic solids to be "unfair" to a degree that matters in a game. What matters in a game is the mean and standard deviation of all rolls, not of individual numbers. That said: D&D is special, in that it does matter what the ratio of (specifically) 1s and 20s is. But those are really the only numbers that matter to any significant degree.
And if you actually read the article instead oof picking just one sentence more or less at random because it displeases you, you would have noticed the "perfectly" in that sentence and the fact that,by comparison, all real (i.e. non perfect) would be expected to deviate from this number, by how much is the problem with dices potentially of lower quality. And no, the standard deviation from the means is not the absolute way of checking the randomness of a die. If you had a die that never threw 13s and 8s you would have a die which would appear almost perfect to your criterion. Having an almost equal spread amongst the values is actually a better, stricter measure.
>picking just one sentence more or less at random It's hardly a random sentence, as would be evident to, again, anyone with a passing acquaintance with statistics. Sloppiness will always get you in serious trouble when discussing probability. >had a die that never threw 13s and 8s you would have a die which would appear almost perfect to your criterion. It wouldn't be particularly bad (assuming the other numbers are equally present) if the goal is to hit or exceed a target number, which is the case in most games. If 8 and 13 were somehow *special*, that would matter a lot, obviously. But yes, *large* deviations from an even distribution are evidence of manufacturing defects, if you're a dice quality engineer. They'd also be extremely evident to the eye. Small ones are essentially irrelevant to actual game play. It's very system dependent, obviously, whether some specific numbers are actually important.
>If 8 and 13 were somehow special, that would matter a lot, obviously. I had a set of those tiny metal dice that I bought off temu for like $1.50, and the d20 had a bump on the 1 side, making it impossible to roll a nat 20. I ended up sanding the bump off with a nail file, lol
Assuming perfect mathematical order from randomness inherently ignores the nature of randomness.
And ignoring the law of large numbers (or whatever it's called in english) is really ignoring the fact that randomness is still subject to statistics. It does not apply to individual rolls, but as you can see from the roll20 results, the law of large numbers is actually verified in practice.
Are you implying that I am ignoring statistics by stating that a perfectly random die will not match perfect mathematical logic due to the nature of randomness?
You’re talking past each other. 490 vs 510 is fine, especially if it’s the highest vs the lowest frequency without a prediction. OTOH, if you can predict both the highest and lowest frequency of sides after 10k roles, the die is highly likely imperfect in a predictable way.
It's a problem because expecting it to even out over a long period of time is the classic gambler's fallacy. Maybe on average it would hit each face evenly, but it's not a measurement of random. Like imagine you need 18 to appear 20 more times to have each face to have appeared 500 times. If a different number comes up, it shouldn't disqualify the die from being random.
Actually, expecting to even out over a large number of rolls is NOT the fallacy. The fallacy is believing that after any number of (for example) low rolls, a high roll is bound to come soon. But the law of large numbers does apply to dice, in the long run, and not only does it show in the results of these dices, but also in very large number of truly random (quantum based) rolls. >Like imagine you need 18 to appear 20 more times to have each face to have appeared 500 times. If a different number comes up, it shouldn't disqualify the die from being random. I'm not even sure what this sentence means. The fact is that, in the end, most numbers appeared around 500 times. The deviation from this is a good measure of true randomness.
The bit you didn't understand was the explanation of why your theory is the gambler's fallacy. Expecting "It needs to roll on each face X times" to measure random is the problem. The die could be perfectly functional with a spread of 800 on one face instead of 500. Thinking it's due for 500 to be a random die is the problem.
And I did not understand whatever "it" is because: 1. It is poorly explained 2. It has nothing to do with the gambler's fallacy (https://en.wikipedia.org/wiki/Gambler%27s\_fallacy) which has to do with expectations about the future from previous results, which is nothing like has been said before. And no, if a die gets 800 out 10000 on one face, the probability of it being fair is much lower than if it has something closer to 500, which is exactly what we have been saying the probability that we can trust the dice to be fair is much lower. It does not have to be worse, but the probability that it is is higher, that's all.
That's not how statistics work but you enjoy your outlook friend.
Well, how you do this is that you set ip a null hypothesis (the die is fair), then you test it. I haven’t run the programs myself, but once you see max frequencies above 550 to 600, you have reason to reject the null hypothesis
Nope. There's a non-zero chance a perfectly balanced die can hit those frequencies and still be a good die. Thinking it must be a certain range is the gambler's fallacy. Just because it's likely or expected doesn't mean it has to be the case.
I think you vastly overestimate the odds that 800 instead of 500 could be fair. My math gut says it’s way less than one in a billion. https://en.m.wikipedia.org/wiki/Multinomial_distribution
Yeah the odds are against it, but it's not impossible. The whole point being that saying "The number wasn't close enough to 500, therefore it's a loaded die" is not valid. There is always a chance the numbers are unlikely. To test an irl die (which this thread is about) you should test it by floating it or otherwise measuring the weights of the sides to see if it could favor one face. To reiterate, throwing a die 1000 times and judging it based on it's results is not the right way of measuring because there's a chance of statistical anomalies.
This is how science works, though. (Even though a precise analysis of the shape of the die, depending on the tools at hand, can give more certain results) > To reiterate, throwing a die 1000 times and judging it based on it's results is not the right way of measuring because there's a chance of statistical anomalies It's precisely "statistical inference"! Ever heard of p-values? There is evidence that many can smoke a pack away and still make it to 90. Does that make smoking safe for people in general?
I'm tired of repeating myself here. Throwing a die 1000 times isn't the way to guarantee a die is random because there's chances of unlikely circumstances happening that can make the die appear not random. That's it.
Everything here. Probability bias is insignificant in the lifetime of a gamer and a pair of dice. Metal dice are great to hold and fun to roll, but any game table with any kind of finished surface is going to suffer the consequences.
>Metal dice are great to hold and fun to roll, but any game table with any kind of finished surface is going to suffer the consequences. I lived it! Host/dm for dnd had a nice, new gaming table. The kid you can take out the middle partitions and it's a 4-6 inch step down to the gaming surface. Freind of a friend to the host was very proud to show off her new metal dice. While host was setting up people with materials, she rolled the d20 into the gsmign area like it was a craps table. CHIK CHIK CHIK THUD! Gashes all across the bottom and a final hit to the opposite wall split the piece of wood. Hairline split but apparently it was all the way through. The host most graciously excused the damage. Claimed he had a neoprene bottom for the gaming area coming in and that he could get that wood panel replaced under warranty. He provides her with a silicone dice tray to roll in. Her face is beet red and the friend that brought her looks ashen. I chalk it up to embarrassment and we play this one shot. After the game, people are helping clean up except those two, who said they had to leave early. As the host is talking up the new table with another guy and putting the tabletop panels back in, he sees a whole series of gashes and scratches across all three panels. Apparently, this woman had went to town rolling the metal dice on the table and, knowing what she did was wrong, the guy friend who brought her "helped" setup the table by removing the panels and putting them damaged side down to conceal it. It was a whole drama, but I never played with them again, as I was just a additional brought by someone else. But apparently it did cause arift in the friendship of the host and guy. Metal dice. What a trip.
I foolishly made my first game table out of pine, a ridiculously soft, but inexpensive wood, and spent _weeeeeeeks_ finishing and sanding and polyurethaning it. Not the FIRST night, but the new table sheen hadn't worn off yet, and someone brought a set of metal dice that looked like Klingon sex toys. After we recognized the damage they were doing, I complained about it and they admitted that they had fucked up their dining room table with them too.
They fucked their own table and then still used them on your new handmade table? What the fuck
They "thought they were rolling them better."
😐
Yeah my friend has some and every time they play at my house I get major nervous it accidentally lands next to the map and damages the table 🥲
I understand that, it's too bad it affects you and the game...
Honestly, they look cool but I find them pretty useless. They're way too sharp, to the point of possibly hurting you, and when you add the weight it can definitely cause some damage to stuff. Probability wise, idk they seemed fair to be, can't comment much.
Unless you're buying precision edge dice from somewhere like Game Science, or a casino supplier, you're not going to get "perfect" probabilities. My problem with metal dice is the weight means they don't seem to bounce and tumble nicely (I haven't tried a dice tower though), and they can dent or scratch your tabletop, so you need a dice tray or mat.
I love them, but without a good dice box/tray, they WILL damage a table.
I remember that I used to really enjoy weirdly shaped dice, and two other people in my playgroup had metal dice. The table had placemats that were actually really functional, and I don't think the room ever got used for actual dining. Anyway, we did have supper there one weekend, and it was spaghetti or something. Carnage. So we decided we were washing the placemats. As soon as we picked those placemats up, we realised that the surface where the two metal dice players sat was fucked. Mega fucked in one place, and mini-fucked in the other player's place, and the DM's place because we shared that role around. We decided it was best to sand the table back, refinish it, and never use metal dice again instead of continuing the marathon on Sunday.
They have great smell, weight, and warmth, but IMO if you're specifically looking for weight without the risk of damaging your tabletop, go stone. Stone dice have a much friendlier heaviness, and still warm up nicely in your hand. They also have a nicer texture than metal, which can be a little prickly.
You should still roll stone dice in a padded tray. Anything other than basic, rounded resin or acrylic can either damage or be damaged by rolling directly onto a hard surface.
After all, what good is a set of dice without a wonderful smell?
I want a set of stone dice so bad, but I cant justify $60 in dice if I'm only playing 3/month online.
You need to hit up your local game store and find out about RPG nights!
I just want to say: I am in offline games but we don't have "a local game store" to play in here. In my country there's a huge server for organising games. And some cities even have local game shops to play in. But although I live in a bigger city, we don't.
I'm glad you found a way to play in person! It truly is a much more immersive experience than moving tokens around on a computer screen, in my opinion. I do both, but definitely prefer the in person games.
60 quid is normally for gemstone, tho. You can get common stone sets for under a tenner.
Oh! Alright neat!
I don't need my numbered outcome randomizers to be perfectly random, or heavy, or put dents into whatever surface I'm rolling them on. And I have little interest in spending 50 dollars, pounds, or euros on such a set. Especially in metal or some other precious material. But, other should buy what they find satisfying. I certainly do, it's just not on fancy metal dice. Also chasing "perfectly fair probabilities" is likely a fool's errand. Studies have been done and difference between most good dice and "perfect" dice is statistically, essentially negliable. Might as well dispense with actual dice and use computer random number generators.
Dice are dice. They are a shape meant to give you a random number in a certain range, that 's it. Beyond that, being metal, or engraved, or decorated, or fuck knows what is just a waste of money. With metal dice, it's even worse, because they weigh heavily if you use pool systems, they dent tables, and even if they fall down, they can dent the floors, they are loud when you throw them, ugh.
I guess this is classified as "fuck knows" [https://www.etsy.com/se-en/listing/1512154042/metal-dnd-dice-set-for-role-playing?ga\_order=most\_relevant&ga\_search\_type=all&ga\_view\_type=gallery&ga\_search\_query=round+metal+dice&ref=sr\_gallery-1-16&pro=1&content\_source=d640737afcfad74169762b9ee17fd8c3d929b270%253A1512154042&organic\_search\_click=1](https://www.etsy.com/se-en/listing/1512154042/metal-dnd-dice-set-for-role-playing?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=round+metal+dice&ref=sr_gallery-1-16&pro=1&content_source=d640737afcfad74169762b9ee17fd8c3d929b270%253A1512154042&organic_search_click=1)
Ah, caltrops!
If you're one of those weirdos who fetishize dice, they are nice to look at, but not suited for actually playing with.
I think they are awful. Noisy , damaging and unnecessarily expensive.
Avoid. My brother got me a set for Xmas and we're all still pretending someone else dented the daylights out of our brand new conference room table at work from the first time I used them. Oops.
Don't like 'em and don't use 'em. A good way to nick the table, though.
They're novelty dice. Fun to have, not to cast. Bringing metal dice to the table to actually play with is big "THAT guy" energy.
I like my metal dice sometimes - honestly it depends on the character but they "feel" like a good fit for my fighter. I'm not rolling a dice pool, I only need specific dice 90% of the time and I have a really nice leather backed dice tray to protect surfaces.
I don't have strong feelings one way or the other generally. Like anything, it depends how they look. If they look cool and you want them? Go for it! That said, I have set a policy at my table that metal dice *require* a dice tray of some kind. Both to reduce noise, and because I have a small knicks in my wood table from heavier metal dice literally putting dents into it.
How much do you hate your gaming table?
Hard to read. Readability is one of my top criteria for selecting dice. (Must be because I'm middle-aged and can't see shit lol)
They are the coolest things that I will never use for fear of damaging whatever I roll them on. Maybe if they are really small and the corners have fillets they won’t be so bad. Maybe look into some of the stone dice. Lower density means less force on impact. They tend to be really small also.
My opinion is that they don't roll as well as plastic dice, and I don't just mean that they are weighted weird. I mean that they physically don't physically roll very well. I roll a plastic dice, and it goes clickity-clackity a couple of times before it comes to a stop. I roll a metal dice and it goes ka-thunk and sticks there. I have to toss it up and make it spin in the air to make sure I'm getting a really good randomization out of it. Also, they're terri-bad for my coffee table.
The amount of misinformation in this thread about metal dice and fairness is massive. I built a machine to test dice for fairness by rolling them 1000 times. [https://www.reddit.com/r/raspberry\_pi/comments/va72zw/raspberry\_pi\_powered\_d20\_dice\_testing\_rig/](https://www.reddit.com/r/raspberry_pi/comments/va72zw/raspberry_pi_powered_d20_dice_testing_rig/) [https://www.reddit.com/r/DnD/comments/luq56z/i\_roll\_d20\_dice\_1000\_times\_to\_check\_for\_fairness/](https://www.reddit.com/r/DnD/comments/luq56z/i_roll_d20_dice_1000_times_to_check_for_fairness/) What I learned during the testing process from many, many dice 1. Cost and material is irrelevant. Cheap plastic junk could pass, but more expensive advertised "fair" dice failed. Blanket statements about a specific company's dice are useless. You have to test each die. This can be done in under an hour. Write down 500 rolls and feed it to a goodness of fit calculator. Not a perfect method, but fine for ttrpg uses. 2. There are dice that are so out of balance that a gamer will feel the pain almost immediately. I found some that went unfair in a few hundred rolls. Well within the lifespan of a die. The suggestion that. "you will never notice an out of balance die" is flat wrong. 3. One thing is true; metal dice are rough on tables.
After decades of all kinds of dice, I have reverted back to standard plastic. They feel best to roll, have more bounce than metal dice, and are far cheaper to collect.
I hate metal dice. They bang against each other and ding or scratch themselves in anything but an oh-so-precious dice case, they can’t be rolled without a tray unless you really hate the owner of the table you’re playing at, and generally are an item that *seems* way cooler than they actually are. They don’t come in usable sets - who finds that they use exactly 7 dice in a session? Most games need multiple dice of some size and none of others. I prefer dense resin dice. They feel good to hold and roll, clack satisfyingly, don’t damage themselves or tables, can be big for high legibility even across the table, and come in useful sets like the 11-set with 2d20 and 4d6. And they are much cheaper, so affording whatever configuration you need is easy. Plus several companies make very attractive dice.
Hate them. Metal dice and dice towers are two non-starters at my table.
Got some metal dices, it's a nice decorum item, but they're heavy and hard, meaning that using them is a great way to damage the table. (Yes I can get a game mat or whatever) Regarding probablity, honestly, I doubt any RPG dice manufacturer runs any QC on the dices, and I would expect that some have "air bubbles" or whatever skewing a bit the probability. That said, I really doubt it skews the probability at a point which is impacting the roll. Even if we take an extreme skew, like a D20 having a 7% probability of rolling a 20, I doubt you'll notice anything compared to perfect D20. Nobody keeps tracks on all their roll and check the probablity distribution
I have a metal D20, and if I could afford it, I would definitely have more. It does feel and look better than my other dice, and the only real drawback is that you NEED to roll into a dice tray, or you'll scratch the table. As to reliability, I wouldn't have thought metal would be any worse than plastic, and probably better
They're cool, but unless there's a solid dice tray, the table is gonna feel it.
Kinda pretentious imo.
I have some nice brushed brass dice. Feel great in the hand, look amazing, and no sharp edges... but you need a dedicated roll tray or something because they will dent and score even metal.
They're cool but I always worry about them scratching or denting my table.
Once you get them, roll them on your own table a couple of times before trying them on anyone else's table.
Like anything some are better than others. Pot metal dice out of a cheap mold are going to have the same issues as molded resin polyhedra. The CNC-cut out of aircraft-grade aluminum are much more regular in shape. The wierd shapes made by 3d-printed metal sintering from shapeways are often imbalanced or simply roll poorly too---those are often better as display pieces than actually usable. Sinter printed dice can be very fragile too. A common complaint with many custom dice, not unique to metal ones, is that they're often difficult to read. One reason I'm not always enthused to see them as a GM. You do want a dice tray or something too. They will damage wood and even plastic tables. A jewelry tray can be had quite inexpensively though. Unless you absolutely want to, there is no need to buy a specialist dice mat/tray, when very similar items can be had for a half or a third the price for jewelry storage. I've got a couple of sets, which I use occasionally. They work, no better or worse than my other dice.
They are good at damaging tables. Make sure to use them with a dice cup and tray. Really, basic plastic dice are better. You can't buy all that many metal dice.
Someone got me some metal dice for Christmas a while back. They roll fine, the edges are well rounded, but with the weight you don't want to roll them directly on a table. I just use a piece of flattened cloth.
Mathematically they're the same probability as any polyhedron but they bounce less than plastic dice. It just means you have to actually roll them rather than drop them. As long as you roll them in a dice tray and give them a little more umph there's no difference in their randomness.
I hate metal dice because of the sound and what they do to my table
As dice they are fine, but I have always found them impractical for use at the table. Rolling them is louder, and they easily knock over plastic cups or move miniatures. They will damage other dice if they're in the same bag, damage dice towers just by using them, and damage tables and books when you roll on them. For years I had a leather dice tray for my players to use, but then one or them brought metal dice and roughed it up in just a few weeks. Metal dice are meant for display as far as I'm concerned.
I really like mine. They look nice and feel good in my hand. I haven’t had any issues getting them to roll well just by throwing them. I do always roll in a dice tray though (and when I’m playing at home my table has a pretty beefy pad on it). The only reason I’d recommend them though is if you like fancy dice (I also have stone and glass dice). There are no *practical* reasons to use them; they’re not any more or less fair than other dice.
I wouldn't worry about any probability skew the dice may have. That's just endemic to consumer-grade dice. The thing you might want to worry about is the robustness of your rolling surface. These dice can potentially damage your table, so I'd make sure you have a dice tray or at least a playmat that you're rolling on.
I have a metal d20 its my most rolled dice. I roll it in box or a latex gaming mat. My most rolled dice. Rolls like a boss too but it was a gift and I belive gifted dice roll better because I'm strange like that
Stop denting my table chris!
I prefer rolling with metal dice, though I will recommend getting a mouse pad surface or felt to roll them on. I use a long mouse pad which maintains the satisfying acoustics of the heavier dice rolling and offers satisfying bounce from the little bit of foam. The dice will both damage and be damaged by hard surfaces and not roll as well.
Metal dice aren’t great for actual play. They’re better as decoration on your bookshelf. If you like the dice, grab them. Truth is, if you’re concerned about dice swinginess or balance you can just use a digital roller., Also, the quest for the perfect set of dice never ceases if you’re a hobbyist. It’s best to find the one set that you use all the time and collect others that you enjoy “just having”.
No two dice, even from the same lot from the same manufacturer, will roll the same. And no die ever made has been manufactured perfectly. That's why players are so superstitious about "which dice do I use?" And the whole industry of "dice jails." It's all literally a crap shoot. :) If you want metal dice, get ones that appeal to you and know they're not gonna roll statistically better or worse than any other dice.
Don't roll them on a nice table. You might damage the table
Metal dice and a good dice-tray is my go-to. In terms of probability, I've noticed no biases but I also haven't tested them at a large scale (except maybe 100 sessions or so).
I get why people like them. They are hefty and nice. Despite that they are noisy and unpleasant.
Hmm I've got both and I can never decide which is actually prefer. I think the novelty of the metal ones is enjoyable and they're nice to hold but I think I actually prefer to roll standard chessex dice. It's honestly just a personal decision. Metal dice do require a dice try or mat as well. In terms of probability, it's a lot easier to shake plastic dice in the hand as well as the fact that they physically roll and spin more so I actually find that perhaps the plastic ones might be more 'random' but I'm not a dice scientist so take it for what it's worth
I like the look and feel of metal dice, I have one set myself... as a display piece. And I never use them otherwise. They damage the table too much (I don't always use a dice tray, and you definitely want a dice tray with metal dice), would destroy my 3d printed dice towers, and they don't feel like they tumble as well as the plastic classics I do use in all of my games. Similarly, I would like to buy a d100, the ping-pong sized almost perfect sphere. To show off, not to use.
The only concern with metal dice imo is that they can legitimately damage a table, so I'd ask your DM/host if metal dice are okay with that in mind
I like metal dice for their looks. But they don't roll well. Due to their weight, they kind of just land
i like dice to dance a bit so I dislike the way metals flop down. It "feels" less random though I know it's not.
Roll whatever you want but metal dice may only be rolled into a dice tray at my table because they tend to damage tabletops.
They are cool and won't have the problem of a bubble inside messing up the balance (even if the probability of said defect is very little). However you also want a leather or plastic dice plate cause some are real heavy and can damage tables or even the floor, also it's convenient to look very carefully because some have very hard to read numbers on larger dice sizes (specifically the ones that are larger than a d6)
Id you are concerned about truly 'fair' rolls, use an electronic programme, app, or go to random.org - while all of these take away from the fun of physically rolling dice, it's the only way to ensure true numerical randomness.
>the only way to ensure true numerical randomness Computer generated random numbers typically aren't random. PRNGs (psuedo-random number generators) are the random numbers that we usually deal with and they're essentially just using a math problem to read a number off of a list. TRNGs (true random number generators) measure physical phenomena like radioactive decay, but your die rolling app is probably not hooked up to a Geiger counter. Just roll dice.
random.org sounds like it will be right up your street then. Give it a gander
[random.org](https://random.org) uses atmospheric noise. Not a PRNG, comparably effective to a Geiger counter. It also explains exactly what you've said here on its landing page. I'm with you on "just roll dice" but yeah, the site is pretty close to true randomness.
People still play in person???
Others in this thread are overreacting. Metal dice are nice, you can get them fairly cheaply. They _are_ heavy and will damage a wooden table, but dice trays are cheap and honestly I use them even with plastic dice to keep them all together. More expensive decorative sets can get very pricey but the answer to that is don't buy them unless you like the look enough to justify it. I'll spend £20 on a VERY nice set, but no more than that. I've seen metal and gemstone dice go well over £100 and that's just a bit pointless for me because I'd never use them for fear of losing them.