alt.hn

4/21/2026 at 6:19:15 AM

Louis Zocchi, inventor of the d100, has died

 https://icv2.com/articles/news/view/62176/r-i-p-louis-zocchi-the-godfather-dice

by sgbeal

4/21/2026 at 12:21:39 PM

>> By far, his most significant contributions to the games industry came in the realm of dice design. Zocchi founded Gamescience in 1974. He was the first to create polyhedral dice for the U.S. market, and is credited with designing the D3, D5, D14, D24, and D100. The D100 was named the "Zocchihedron" in his honor (see "Have A Nice Day!").

And I happen to own at least one of each of those specialist dice. And many more still. I think I have a die with faces for most even numbers from 2 to 100 and also some of the odd ones too.

OK now you all know I'm a nerd.

by YeGoblynQueenne

4/21/2026 at 7:15:44 AM

More than just the d100 he was a pioneer of being very exacting when it came to making polyhedral dice. See http://www.1000d4.com/2013/02/14/how-true-are-your-d20s/

by guyzero

4/21/2026 at 7:31:57 AM

> More than just the d100 he was a pioneer of being very exacting when it came to making polyhedral dice.

Absolutely, but i couldn't fit all of that into the subject line ;) and he's best known for the d100. Many of us remember the articles and ads from the 1980s describing the effort he put into that particular die.

by sgbeal

4/21/2026 at 9:04:02 AM

The amount of games that use those kinds of dice make his contribution to tabletop gaming incommensurable. Sad to see him passing. But 91 yo is more than respectable

by tgrover

4/21/2026 at 12:19:52 PM

The "Zocchihedron" is a single die with 100 sides, but most games that use a d100 simulate it with two d10s instead (reading the ones on one d10 and the tens on the other). So the truth is that Zocchi's die is more a novelty and less influential than it might appear at first if you take the title as written.

by YeGoblynQueenne

4/21/2026 at 12:29:51 PM

Yeah, a real d100 is just too impractical for actual gameplay. Super neat, but two d10s is far more usable.

by estimator7292

4/21/2026 at 9:40:41 AM

91 is respectable for a reasonable man in the early 21st century. A few unreasonable people want a bit more.

by melling

4/21/2026 at 12:27:32 PM

Nothing unreasonable about wanting to live healthy and longer. It's not likely tho.

by zulban

4/21/2026 at 10:29:26 AM

And most of them will die before turning 91. Like most people.

by jrflowers

4/21/2026 at 11:30:19 AM

Those of us already over 40 already thats maybe the best we can expect, for 20 y/olds who knows..

by tonyl

4/21/2026 at 12:01:37 PM

> But 91 yo is more than respectable

And it still fits on a d100!

by TacticalCoder

4/21/2026 at 9:25:31 AM

It had never occurred to me that somebody needed to invent polyhedral dice. There must be so many inventions in the world that I’m completely unaware that there was a point in time before which something didn’t exist and after that it did, thanks to somebody.

by sd9

4/21/2026 at 10:40:35 AM

There are only 5 Platonic Solids https://en.wikipedia.org/wiki/Platonic_solid : D4, D6, D8, D12 and D20.

There are 13 more solids with equal faces and vertex (but not equal edges) https://en.wikipedia.org/wiki/Catalan_solid but none of them has 100 faces (It looks like a nice project for 3D printing.)

You can cut the corners, but now the faces are different and ensuring all the faces have the same probability is a nightmare. Some info in https://en.wikipedia.org/wiki/Truncation_(geometry)#Uniform_... (This include the soccer ball.) (I have no idea if this include the D100.)

You also can "cheat" and use https://en.wikipedia.org/wiki/Teetotum that allows any number if you don't care too much about the polyhedral property.

by gus_massa

4/21/2026 at 11:57:07 AM

The Zocchi d100 isn't face-symmetric and thus isn't a fair die. It's as close as he could get. It's really effectively a golf ball with 100 dimples, but they aren't and can't be arranged perfectly symmetrically.

Any even number dX can be made as a fair die as a bipyramid or trapezohedron. https://en.wikipedia.org/wiki/Trapezohedron These would be the only fair face-symmetric d100s. The standard d10 is this, and you sometimes see a d14 or d18 or something like that constructed this way. It becomes impractical with very thin faces past 20 or so. An odd-numbered fair die is also possible by using one twice as big and duplicating the numbers (like 1-5 twice on a d10.)

by vikingerik

4/21/2026 at 9:36:50 AM

Everything you've ever seen that isn't sky, water, air, ground, life was invented by someone.

Heck, many specimens of the last two are inventions, that are insignificant as a % of species but are in the worldwide top by biomass.

It's quite difficult to leave the anthroposphere in much of the world.

by literalAardvark

4/21/2026 at 10:21:25 AM

The internet reports that D100 is impractical to use but it's cool if your game design calls for a relatively rare "ritual value".

by praptak

4/21/2026 at 11:32:38 AM

> The internet reports that D100 is impractical to use...

It's a nice novelty but it's not terribly practical. Despite having a d100, 2d10s are invariably more comfortable to use and easier to read. My d100 was purchased back in 1998-ish for its novelty and nostalgia value, not its functional value.

by sgbeal

4/21/2026 at 11:41:34 AM

Here I was thinking he invented throwing two d10 where the other one is marked with tens.

Somebody had to invent that too, right?

by pavlov

4/21/2026 at 7:22:20 AM

https://en.wikipedia.org/wiki/Zocchihedron

I didn't see a picture of Zocchi's d100, Wikipedia has one

by 01HNNWZ0MV43FF

4/21/2026 at 8:09:07 AM

Interesting they had to redistribute the numbers to take account of its natural bias.

by pcblues

4/21/2026 at 8:55:51 AM

Sort of crazy they didn't test it for bias before they released it!

by philipallstar

4/21/2026 at 8:08:22 AM

I just throw 17d6 and subtract 2.

Problem solved.

(I am joking!)

by pcblues

4/21/2026 at 10:12:36 AM

Joking aside, is throwing 2d10 and using one for tens and one for units different from throwing 1d100?

by klez

4/21/2026 at 10:49:33 AM

Throwing 2d10 of different colors is equivalent of trowing 1d100. It's nice they have different colors to avoid discussions, but you can throw them in two different bins or one at a time or something. Remember to sum them as (x-1) * 10 + (y-1) + 1, that is a clear indication of why zero-based indexing is better.

(Does someone sell "decade" dice, which faces say: 10, 20, 300, ..., 90 and 100?)

by gus_massa

4/21/2026 at 10:58:27 AM

> (Does someone sell "decade" dice, which faces say: 10, 20, 300, ..., 90 and 100?)

Yes, they do. I used to use them for this exact purpose.

by klez

4/21/2026 at 10:34:12 AM

I would say yes, because the physics of rolling two objects is slightly different than one object. I don't have any idea, though, if that would affect the distribution of numbers rolled. It's not an experiment that can be done through simulation.

by bovermyer

4/21/2026 at 8:16:00 AM

I've never played any games that require this, but the Wikipedia page makes reference to percentage rolls, but wouldn't you need 101 sides to get 0% and 100% for that?

by benj111

4/21/2026 at 8:21:48 AM

> but wouldn't you need 101 sides to get 0% and 100% for that?

There is no 0% in d100/d-percentile rolls. Every "how to interpret these dice" paragraph in games which use them will tell you to interpret 0-0 on 2d10 as 100, not 0. Or, hypothetically (but i don't recall having ever seen this), they'll have a stated range of 0 to 99 (inclusive). Either way, the numeric range spans precisely 100 digits.

by sgbeal

4/21/2026 at 12:23:39 PM

There are games that use a d100 with 0-99 range, and games that read a d10 as 0-9 for that matter. First that comes to mind is Ambush! from 1983 that did both those things (https://boardgamegeek.com/boardgame/1608/ambush).

Love that game, but it is a bit distracting that probabilities feel one-off. Rolling 5 or lower to hit is 60%, not 50%. And when rolling 2d10 the result is 0-18, not 2-20.

by 1313ed01

4/21/2026 at 10:01:18 AM

yeah but that means there is no 0% on the scale

by PunchyHamster

4/21/2026 at 10:38:36 AM

The point of percentile dice isn't to generate a string between "0%" and "100%", it is to test if action with chance of x% success gets done or not. For every o value of x, there are x out of 100 values which are strictly less than x, or if you count 0 as 100 then there are x out of 100 values which are less than or equal to x. Either way you get x% percent chance for event to happen. If the dice had 101 sides, the probabilities would be x/101 which aren't nice round percents.

It even works correctly for 0% and 100% chance events. Assuming 0 is counted as 0 - For 0% there are 0 numbers less than 0 on dice so chance of throwing number less that is 0/100=0%. For 100% all 100 numbers are less than 100 so no matter what the result of throw is you will succeed.

by Karliss

4/21/2026 at 12:22:05 PM

Not necessarily "done or not" because it's narratively unsatisfying to just "fail". Imagine you watch a heist movie and in the last 20 minutes the gang are like "Stealing the master key to make a copy was vital to our plan but we failed" and they disband and that's the end of the movie. Realistic but not satisfying and the dice are for a game, a fiction, so we can just eliminate that unsatisfying result.

Modern systems tend to come up with some more interesting consequences, so e.g. maybe success is the thing the player wanted to do succeeds as they expected, but failure shades from "Small snag" to "Technically it did work, but..." like from "The target's PA, Betty, noticed you take the key, so now you also need to bribe Betty" through "Our copy won't actually work, we're going to need to keep the original and hope the copy fools them for long enough"

Or maybe we have a timing adjustment, success means that you pilfer the key, duplicate it in five minutes like planned and slip it back, mild failure is it takes a half hour and everybody will need to improvise for those extra minutes, and bad failure is you'll need it all night, change your plans to accommodate that.

by tialaramex

4/21/2026 at 10:03:48 AM

No, because in d100 based systems you success is rolling at or below a chance.

So the fact there is no 0% (0 is interpreted as 100) is necessary because if your modifiers are giving it 0% chance, you need dice to start at 1 for that to work

by PunchyHamster

4/21/2026 at 9:26:22 AM

The study of imperfection in dice that makes them settle on certain favoured numbers by Louis, helps clear superstitious story of Mahabharata whereby the character named Shakuni, had dice made of his dead father's ashes who/which always respects/fall on numbers he desired,threby winning/cheating in game of Chaupad, that ultimately lead to biggest war in human history

by G_o_D