Or, disdyakis triacontahedron

April 30, 2016 12:07 PM

Introducing the d120

The New Yorker covers the creation of the "ultimate fair die allowed by Mother Nature."

Interestingly, the die can be used as a substitute for all the commonly used gaming dice.

posted by ChurchHatesTucker (33 comments total)

I recently decided to venture back into tabletop RPGs (after nearly twenty years away) in the hopes of getting my young daughter hooked. And in the midst of preparation, I am constantly reminded of how long it has been and how much older I am now.

And so the first thing I thought when I clicked the video was, "Jesus, my eyes. I can't read that fucking thing!"
posted by AlonzoMosleyFBI at 12:14 PM on April 30, 2016

Ha, that's pretty fantastic. It's easy to say "but that's hardly useful", but great big dice aren't really about that (and dice at all are pretty silly if strict utility is your goal). I like the thoughtful approach to face number distribution, in any case, and thedicelab's design notes for their various dice is interesting.

Also, I had the same thought that the New Yorker bit quotes George Hart on: the more faces you've got on a die, the more subtle the manufacturing discrepancy required to produce probabilistic unfairness. Small angles, small faces, slightly off ridges, etc. And I love this little side-jaunt from that same bit: testing the fairness of d20s, using a custom dice-rolling machine and a bunch of statistical analysis.
posted by cortex at 12:24 PM on April 30, 2016 [3 favorites]

I like the suspense involved in painstakingly figuring out which face is really on top for every roll.
posted by zachlipton at 12:26 PM on April 30, 2016 [2 favorites]

My favorite part of the video: "Whoops!" There's nothing quite like doing a live demo.
posted by ubiquity at 12:31 PM on April 30, 2016

What was wrong with a d12 and a d10?
posted by Talez at 12:33 PM on April 30, 2016 [1 favorite]

You could do some serious damage with that thing.
posted by Flashman at 12:38 PM on April 30, 2016 [4 favorites]

What was wrong with a d12 and a d10?

This one goes up to 120.
posted by ChurchHatesTucker at 12:43 PM on April 30, 2016 [22 favorites]

What was wrong with a d12 and a d10?

Sure, for you compu-math geeks who are comfortable with formulae like "d120 = (d12-1)*12 + d10", and don't mind running after two dice instead of just one when your five-year-old screams maniacally and throws them both as hard as he can.

But I'm also reminded of what two great men once said in the classic film Dodgeball:

Peter: ...Are you sure that this is completely necessary?
Patches O'Houlihan: Necessary? Is it necessary for me to drink my own urine?
Peter La Fleur: Probably not.
Patches O'Houlihan: No, but I do it anyway because it's sterile and I like the taste.

So just enjoy it.
posted by ubiquity at 12:45 PM on April 30, 2016 [4 favorites]

My order of dice from them arrived on Monday!

I didn't get the d120, but I was definitely tempted.
posted by mikurski at 12:49 PM on April 30, 2016

I ordered one of these soon after seeing the New Yorker article. Along with some of their other dice.

I have no use for these, as I don't play RPGs any more. But I felt a deep, passionate need for this die. After considering this urge, i went onto eBay and bought a package of assorted Mardi Gras doubloons, and will be hitting a local game shop to buy a bunch of gem dice. Because I have apparently reached a point in my life where I simply want a sack full of Fake Treasure that you could also theoretically use as a source of random numbers to tell a cooperative fantasy story.
posted by egypturnash at 1:29 PM on April 30, 2016 [5 favorites]

I remember everyone buying 100 sided dice when they came out way back when before color TV and we still wore onions on our belts.

We all bought some, then rolled percent chances the good old fashioned way with 2 d10s anyways.
posted by Max Power at 1:56 PM on April 30, 2016 [3 favorites]

d120 = (d12-1)*12 + d10
fwiw, should be d120 = (d12-1)*10 + d10 (maybe obvious, but i was thinking you'd take the product of the two, then realised that wouldn't work, then couldn't see what you were trying for, for a moment).
posted by andrewcooke at 2:09 PM on April 30, 2016

I had a nerdgasm upon learning that, yes, the opposite faces do add up to 121.
posted by Robin Kestrel at 3:04 PM on April 30, 2016

When I got my D100 I thought I had all the dice I needed. I was wrong.
posted by Splunge at 3:31 PM on April 30, 2016 [1 favorite]

I'm going to need a bigger bag of holding.
posted by chimpsonfilm at 4:07 PM on April 30, 2016 [4 favorites]

Interestingly, the die can be used as a substitute for all the commonly used gaming dice.

I think this advantage is offset by it taking up the same space in a Crown Royal Bag, and of course the extra 45 minutes necessarily allotted in each gaming session waiting for the fucking thing to stop rolling.
posted by ricochet biscuit at 4:19 PM on April 30, 2016 [2 favorites]

Pfft. You guys only want a d120 'cause that's what Big Dice wants you to think.
posted by the quidnunc kid at 4:42 PM on April 30, 2016 [2 favorites]

The real story here is that the New Yorker style guide permits the dn nomenclature without explanation.

Nerds.
posted by The Gaffer at 5:30 PM on April 30, 2016 [8 favorites]

Whereas the New York Times would insist on referring to the various dice as "Mr. 6", "Mr. 10", "Mr. 120", etc.
posted by cortex at 5:32 PM on April 30, 2016 [16 favorites]

A D120?

I guess it's time for Rolemaster to update Arms Law.

(Rolemaster's still a thing, right?)
posted by Mezentian at 6:05 PM on April 30, 2016

The d120 is billed as the “ultimate fair die allowed by Mother Nature (i.e., mathematics!),” since a die couldn’t, practically speaking, possess more sides...

ahem...
posted by jpdoane at 6:25 PM on April 30, 2016 [1 favorite]

Ah, but the video discusses that; he notes that either a trapezohedron (though I don't recall if he uses that word) or a simple columnar polyhedron could in principle have more fair sides but the things would just roll around forever at any kind of high face count.
posted by cortex at 6:36 PM on April 30, 2016

Columnar with ballast inside would win the dice challenge, before they banned it with a rules change.
posted by nom de poop at 6:44 PM on April 30, 2016

I remember when the Dragonbone LED dice roller was the height of dice technology.
posted by blahblahblah at 8:15 PM on April 30, 2016 [6 favorites]

a die couldn’t, practically speaking, possess more sides

None. None more sides.
posted by Harvey Kilobit at 8:46 PM on April 30, 2016 [2 favorites]

I loved this! Thanks for sharing it.

My kids have just gotten into D&D. They'll like this too.
posted by not that girl at 8:53 PM on April 30, 2016

I remember when the Dragonbone LED dice roller was the height of dice technology.

So...wanted...
posted by Ogre Lawless at 9:57 PM on April 30, 2016 [1 favorite]

I had a nerdgasm upon learning that, yes, the opposite faces do add up to 121.

Huh, never occured to me before, but I guess the opposite sides of an n-sided die (for all even n's) can always be arranged add up to n+1, because:
(n) + 1 = n+1
(n-1)+ 2 = n+1
(n-2)+ 3 = n+1
... and so on.
posted by sour cream at 3:21 AM on May 1, 2016

Somebody should make a circuit containing a Johnson noise-based hardware RNG and a nice LCD digit readout with adjustable scaling for anywhere from 1-6 to 1-120, and constructed in the form factor of a dice.
posted by Rhomboid at 12:14 PM on May 1, 2016 [1 favorite]

a dice

*twitch*
posted by ChurchHatesTucker at 4:55 PM on May 1, 2016

The Oxford dictionary says 'dice' is both the singular and plural in modern standard English. I even looked it up before posting because I can never remember.
posted by Rhomboid at 7:30 PM on May 1, 2016 [1 favorite]

Wired covers the number placement.
posted by ChurchHatesTucker at 10:21 AM on May 10, 2016

Rhomboid: "The Oxford dictionary says 'dice' is both the singular and plural in modern standard English. I even looked it up before posting because I can never remember."

Well it also says die is correct which is good because I thought I was going to disagree with a dictionary for a minute.
posted by Mitheral at 10:55 AM on May 10, 2016