Why no d18's?

Bohandas

Adventurer
I just tonight learned that d18's were not only a thing, but a thing that dates back quite a while and it got me wondering about why modern roleplaying games, with all their unusually numbered dice, don't seem to make any use of them.

Is it an oversight? Is it because it's considered too close to the d20 to make a difference? Is it because its not a platonic solid? Are they more expensive to manufacture than the other shapes? Is there some other reason?

Anyone have any info on this?

EDIT:
And on a tangentially related note, how come RPGs use d3's but not d5's; it seems like those should be the same principle as each other; one's a d6 divided by 2 and rounded up, the other's a d10 divided by 2 and rounded up
 

aramis erak

Adventurer
EDIT:
And on a tangentially related note, how come RPGs use d3's but not d5's; it seems like those should be the same principle as each other; one's a d6 divided by 2 and rounded up, the other's a d10 divided by 2 and rounded up
The games I've seen using d5's tend to use only d10's... albeit often in d100 mode and occasionally d1000 mode
The BI/FFG 40K line uses only d10's... and did so as an outgrowth of...
WFRP 2E.... which moved to d10's only...
FASA Trek d10's only.

Most games using d3's are either d6 only, d6 & d20, or d6 and d10 (usually percentile).

The thing is, d5 is a hassle most of the time. The only game I've played where the D3 was used often enough as a d3 to make having a physical one was Hero System.... Tho' Fudge and Fate technically uses 4d3-8 by default...
 

Thakazum

Explorer
People are stuck in their ways. Any deviation from the normal polyhedral set is met with disdain. See reactions to DCC's "funky dice" (i.e. non-standard polyhedrals).
 
L

lowkey13

Guest
This article is a really good starting point and may help you with the “no d18s”.

 

JeffB

Legend
Gamers are so weird when it comes to dice (and a great many other things).They think nothing of a standard polyhedral set (which in the grand scheme of things ARE weird) But god forbid you mention having to use DCC's extended set or "Special" dice like FFG Star Wars or whatever- the comments get ridiculous- "Heresy, I would NEVER play a game with those...." :indignantlookwithnoseheldhigh:

Then again Ken St. Andre & Marc Miller balked at the Polyhedral set- so that's really hardcore.

Personally I love DCC's dice step system utilizing all the "Weird" polyhedrals for multiple actions (and especially it's usage for the Warrior class) and FFG's dice system is brilliant and takes about one session to learn. I'm guessing TOR and FATE would be the same.
 
I have d14s, d16s, d18s, d22s, d24s, and d30s.

If I still played 3.x, with its dice scaling, they'd be very handy since I could smooth out that progression (rather than having 1d12 jump to - what was it - 2d8?). As it is, I don't think I've ever had occasion to use them, but I periodically consider the idea of making a game that does (not for distribution, just for fun). I suppose I could just play DCC (which I would love, but I haven't had any luck selling it to any of my groups).

As for why they aren't used? A d20, with its 5% increments, is good for basic resolution. It's easy to work with. As for damage dice, even a d12 is very swingy. It's not that the d14-d18 range is worthless, but it is kind of specialized. Very swingy, without the ease of use of the d20s increments.

Also from what I understand, the molds used to make the dice can be quite expensive, so without much demand it's a very niche market that isn't necessarily going to be worth the expense using traditional models.

This is the KS I backed a few years ago, which was for manufacturing d14s and d18s. That worked, obviously, since with KS you can raise the money for the molds using what amount to presales. They talk a little bit about the process, in case you're interested. Spherical D14 and D18 - the missing even-sided Game Dice
 

Umbran

Mod Squad
Staff member
Is it an oversight? Is it because it's considered too close to the d20 to make a difference? Is it because its not a platonic solid? Are they more expensive to manufacture than the other shapes? Is there some other reason?
Well, for one thing, a d18 is not terribly different, in terms of odds, than a d20: 5.555...% per side, instead of 5% per side. Half a percent isn't compelling.

But also - while there are a handful of examples of strange dice, the vast majority of games use something in the d4,d6,d8,d10,d12,d20 set. Since the 80s, those dice have been fairly common and easy to get. Anything outside that - you need to produce those dice, and expect your new players to buy them, before they can play your game. Your dice mechanic has to be really special to make that a winning proposition. A small variation in the odds granularity is not very special.

EDIT:
And on a tangentially related note, how come RPGs use d3's but not d5's;
Well, in general... they don't. Compared to the number of games extant, the number who use d3s is... very small.
 

Bohandas

Adventurer
Well, for one thing, a d18 is not terribly different, in terms of odds, than a d20: 5.555...% per side, instead of 5% per side. Half a percent isn't compelling.

But also - while there are a handful of examples of strange dice, the vast majority of games use something in the d4,d6,d8,d10,d12,d20 set. Since the 80s, those dice have been fairly common and easy to get. Anything outside that - you need to produce those dice, and expect your new players to buy them, before they can play your game. Your dice mechanic has to be really special to make that a winning proposition. A small variation in the odds granularity is not very special.



Well, in general... they don't. Compared to the number of games extant, the number who use d3s is... very small.
Dungeons & Dragons uses d3s. For unarmed damage and a number of other things.
 

RogueJK

It's not "Rouge"... That's makeup.
The only game I've played where the D3 was used often enough as a d3 to make having a physical one was Hero System.... Tho' Fudge and Fate technically uses 4d3-8 by default...
D&D 3/3.5 and Pathfinder used d3s. Off the top of my head, some 0-level spells had d3 effects, and Medium weapons with 1d4 damage did 1d3 damage when sized for a Small character, or when a character was under the effect of Reduce Person. There are probably a few more examples.

I have a couple of the rounded triangular ones laying around, though they tend to roll kind wonky. d6s halved and rounded up, or even custom d6s labeled 1-3 twice, work better.

But then, I don't like how d4s roll either (especially in a dice tower), and prefer d12s labeled 1-4 three times. So maybe I'm just weird.

Here's a photo of the type of d3 I have:
 
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aramis erak

Adventurer
D&D 3/3.5 and Pathfinder used d3s. Off the top of my head, some 0-level spells had d3 effects, and Medium weapons with 1d4 damage did 1d3 damage when sized for a Small character, or when a character was under the effect of Reduce Person. There are probably a few more examples.
Not common enough, for the limited play I had of 3.x, to justify a physical, especially since the cases where it was needed, it wasn't usually combined with other dice. But some, especially halfling players, might be using it enough to want it.

Hero, however, often has 4.5 or 5.5 or some other n.5 die rolls for damage, all dice being d6's or d3's. And, if you have a power that (due to point increases) is at a half die, and one you use often, it's just so much easier to use the doublemarked d6 (1,1,2,2,3,3) than to remember "this other die is the half-die"...

I'll note that Mongoose RuneQuest also has d3 weapon damages, but... the damage modifiers are one of: -d8, -d6, -d4, -d2, d0, d2, d4, d6 ,d8, d10; Chaosium RQ3 used: -d4, d0, d4, d6, 2d6... there are some d3 weapons. If I'd run more of it, I'd have wanted one for it.

my "physical" d3's are all doublemark d6's. I still have the "d10" that came with RQ3... a d20 doublemarked. I used red and black lab markers to make it useful as a d20....

Which raises another reason d5's were rare in earlier games - the d10 as we know it now was not readily available; use as a d10 was already nuisance enough for many.
 

MNblockhead

A Title Much Cooler Than Anything on the Old Site
I wonder if there is a psychological component. d4, d6, d8, d12, d20 map to the platonic solids, which have symmetries that make the aesthetically pleasing many/most people.

d10s give an easy way to do percentiles.

There are many things from OD&D that have benefited from adjustments, but the original dice set have stood the test of time.

While I enjoy DCC and enjoy the funky die, they never feel "right" to me and that alone would keep that system from being my main go to. I don't even like non-tetrahedron d4s and my main die set have the colors match the medieval alchemy colors for the platonic solids, except that I use black for my d12.
 

der_kluge

Adventurer
From what I understand, Gygax ordered the dice from a teacher's supply outlet. They sold the set of dice we currently use, mostly because those were all the classical 3-d objects. I forget what math term they use for them - all faces are the same shape and size.
 

aramis erak

Adventurer
From what I understand, Gygax ordered the dice from a teacher's supply outlet. They sold the set of dice we currently use, mostly because those were all the classical 3-d objects. I forget what math term they use for them - all faces are the same shape and size.
Actually, the ones Gygax ordered originally lacked the d10.

While the modern shape d10 was patented in 1907, it wasn't widely used, and wasn't readily available, until the 1980s; even into the 80's, many 20-sided dice were numbered 0-9 twice. Space Opera, for example, included 1cm d20's with no 10's place indicator. (And they were not durable... they were soft plastic, and the clothes dryer was hot enough to melt them.)

By 81, the standard $4 TSR set had the modern shape, and other companies followed suit.
 

Hussar

Legend
Hey, I still have one of those d20's numbered 1-10 twice. :D

But, yeah, I think we can point to D&D for the reason why you have the "standard" dice set. Economies of scale and all that.
 

tomBitonti

Explorer
It doesn't look like all of the faces on a d18 have the same chance of being rolled. The two distinct sets of faces, six of one and 12 of the other, each which will have different odds than each other.

D3 isn't that common, and can be rolled as a D6 mod 2. Or, by rolling a D4 until a number other than 4 is rolled. My experience with other players is that they rather don't like either of these mechanisms. That seems to have to do with high verses low facility with numbers.

I don't know if I've ever had to roll a D5. Maybe, if to pick one item out of five. Instead of rolling a D5, I suspect the vastly preferred alternative is to convert the range into a D10 (or D20 or D100) and roll that instead.

Thx!
TomB
 

MNblockhead

A Title Much Cooler Than Anything on the Old Site
From what I understand, Gygax ordered the dice from a teacher's supply outlet. They sold the set of dice we currently use, mostly because those were all the classical 3-d objects. I forget what math term they use for them - all faces are the same shape and size.
They are platonic solids. That's one reason there were no d10s in the set Gygax bought. While a d10 does have faces the same size and shape, it does not have same number of faces meeting at each corner.
 

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