Is the d20 ~feel~ irreplaceable?

Tinkering with my own system (aren’t we all?) I’ve slowly converged to a set of core mechanics centered around the d12 - it’s elegant, rolls well and mathematically fits the way I set up partial success results.

However, there’s this nagging feeling that the d20 is a fundamental part of the OSR/DnD feel. Whether it is purely due to familiarity or something deeper, I don’t know, but judging by the choice of dice in most OSR(-adjacent) games I am not alone in this.

So, I ask: How does the d20 feel to you? Why do you (dis?)like it? And is it irreplaceable?


Hi! My take is that the d20 feel is replaceable. It’s probably a matter of what we are used to feeling. All my games use d6 only. Then again, I don’t really aim at the D&D feel very much, so perhaps I should not have answered.

D6 with pips, that’s the way for me!


I think it’s just a good probability distribution. It’s uniform, and a wide enough range to “feel” sufficiently random, but not as swing-y as a d100. Likewise, while d100 is arguably the most intuitive on-face in that it’s a 1-1 conversion to probabilities (if the resolution is roll under 70, with no modifiers there’s a 70% probability of success), d20 can be multiplied by 5 to convert it into terms of probabilities, and units of 5 are also easier to conceptualize (65% vs. 70% is at least somewhat more tangible than 69% vs. 70%).

There may be more ephemeral aspects, like the literal “feel” or look of the die itself. Also, by sticking closer to previous products, it’s easier to convert between them, so that might be part of the d20 popularity as well.

Without getting too over the top with it, I like when games intentionally play with the probabilities, like in some cases using d20 or in other cases 3d6, which is a similar range but normally distributed rather than uniformly. When done conscientiously it can be really clever and fun.

Now that we have digital random number generators, it would be cool to see people play around with a wider variety or more complex kinds of distributions, but for the most part, I think the simplicity is an asset.

I think it might be overly sentimental to say it’s “irreplaceable”, but there’s not necessarily any reason to replace it in any widespread way, although certainly people should be encouraged to experiment on a project-by-project basis.

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I bounce back and forth between the d6 and the d20.

D6s are UNIVERSAL. Monopoly, Yahtzee, Settlers of Catan, Liar’s Dice, and more. People are familiar with them. Many people have a set in their house, even if they’re not “gamers.” Personally, I like the feel of 2d6 more than 1d6. Rolling just one die feels so weird, UNLESS it’s online. Then it feels fine.

D20 are forever entwined with the Fantasy Role-Play mindset. If you’re looking to speak directly to that audience, yeah, do the d20.

The board game Root uses 2d12, which feels especially nice to roll. Try it sometime.

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TLDR: I like d12s more than most. d20s are not essential to me. In fact, I avoided collecting them for years, because I just didn’t need them for the games I liked.

I’ve grown much more appreciative of d12s over the past year. I think the common impression is that they are:

  • Physically awkward: Not true. It rolls way better than a d8, for instance
  • Ugly: Not true. Has this reputation because honestly, most of the d12s you see in the wild came from a bulk set, and are poor craftsmanship. I have some really nice d12s now!
  • Obscure (in games): Not true. But has this reputation because few weapons or spells use it in *that famous game
  • Obscure (in real life): in terms of being hard to find. Unfortunately, this one is true. The ability to get, say, four or more d12s usually requires buying a whole set of dice, depending on where you shop. Even then … the physical quality of these dice tends to be mediocre.

(And that’s even before you’re printing your own funky, non-numerical d12s … like the new edition of L5R. Lol!)

12 is divisible by 4 (and therefore can be printed as a superior d4), divisible by 3 (and is often used as a superior Fate/Fudge die), and is divisible by 6, 2, 1, and itself. This can be pretty convenient for mapping onto random tables for instance:

  • like d12 x d12 = 144 combinations (featured very prominently in the book Perilous Wilds)
  • d12 x d20 = 240 combinations. And can “collapse” to simulate, say, a d66 by assigning rows and columns to two integers at a time. Etc.

Disclosure: I am not usually a mathy person. Sorry for being sooo verbose today! I just like random tables and click-clack rolling rocks!


That’s an interesting point about base 12- so often underappreciated.


The d20 is iconic and I personally love the d20 and design my games around it.

I also really like 2d6, d100, and Fudge dice. I would probably give any core mechanic a try. (Unless it’s built around d4s, screw that!)

There is something about a d20 that signals “this is D&D” in my lizard brain. But not every game needs to fall into the “not D&D D&D” genre.


I have always loved the d12 even more than the d20.

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The nagging that you’re feeling has nothing to do with OSR-ness or D&D-ness and everything to do with force of habit.

I’m sure if you rolled d12s for long enough, you’d get used to it. Or, maybe you’d rather rework your game to use d20s because it’s what you’re already used to.

Ultimately it makes very little difference.

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“Fire together, wire together.” I think the pairing is as strong as your association with those two activities.

For another example related to rolling the dice, one of the biggest reasons Cairn/EB/ItO is tough for people I’ve interacted with to get a handle on it is the fact that it’s roll-under. They’ve looked so long at a 20 with dopamine shooting through their brains that they feel actual discomfort when they realized they just crit-failed, not the reverse. The association with 20 as “HELL YEAH” getting spun on its head hurts folks, which hurts the presentation of the game.

The association makes all the difference.


Loving the long term potentiation reference :wink:

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IMO d20 is totally replaceable. When I find something that uses a not-d20 I am immediately intrigued. Personally, I love d6s since, as mentioned above, they are more universal as far as all board games are concerned, and rolling lots of them feels fun. d12s never get enough love in major systems. :frowning:

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The association of 20 with that rush is something I can understand, but I don’t feel. When I left gaming before, it was prior to the d20 boom. There were so many different uses of different dice, with d6 having a lot of the attention. Double 1s or double 6s on 2d6 may have had the same feeling as what you are describing. To your fellow players who can’t get a handle on roll-under, I guess they should play more different kinds of games! :grinning: Not a bad thing to do!

Anyway, my conclusion is that this d20 feeling is perhaps generational. There’s before and after 3e + OGL, and the year that is the threshold is, quite neatly, 2000 A.D.


I like d20s. I also quite like d12s. I think the d20 thing is valuable but replaceable. Keeping d20, however, does offer two advantages (though other factors can certainly outweigh them):

  • greater granularity, if you want it
  • greater ease for using/converting the yabzillion published pages of game materials built around a d20. For example, I’m leaning toward Knave as the base for my next kids’ campaign, since it means I can grab extant monster manuals and published adventures to save me time. Cutting the d20 is fine, but requires some thought about how to/whether to port in extant content.

Definitely not irreplaceable, but it’s one of the easiest to design with and use in play. If your system is roll under and something has about a 30% chance of success, you need a 6 or less. If something makes it 5% more likely to succeed, add one to the target or subtract one from the roll. Whether you come at the percentage chance through refereeing or through system calculations, it’s really easy to keep in your head.

Add 1 to a 3d6 bell-curve-ish roll, or add a die to a dice pool, and the odds are slightly less intuitive to calculate. Technically a 1d100 is even easier to understand, but most of those systems modify rolls by adding 5 or 10 per cent anyway, which is just as easy with a D20.

So I think D20s are more than just (cargo) cultural artifacts of the hobby; they’re powerful, easy-to-use tools for refereeing games. But there’s more to games than that, and a dice mechanic that evokes the setting or is just fun the play with is worth getting the feel for.


As others have said the D20 is so nice because it maps easy to percentages. And of course trained brain. I do like the 12 better, it’s my favourite dice. But whenever I try to work with it I fail to create something interesting with it, or something that could not be done nicer with a D20. I would love more D12 games, but they tend to be roll under which I don’t like much. For the trained brain reasons.

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I think that’s a good point, @Chaosmeister . So the d20 for me is definitely more in line with percentages, but I also like d12’s for more nuanced skills checks. I lovingly (stole) and slightly modified some abilities checks from a blog called Cyclopeatron and have them in my house rules and I use the d12 for multi-ability checks often!

However, as a result I have converted most percentage skills (OSRIC/2e style) to 5% point blocks for bonuses to checks. I explain in that wiki page.

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