Odd Dice Math
by Ryan Keane
On the Cheapass e-group, people are always asking how to hunt down non-standard dice, so I thought I'd write up a quick list for the Beat People Up site on how to fulfill your odd dice needs by using blank dice. Credit should go to Glen Barnett and Ryan McGuire, among others, who also came up with many of these ideas.
For most of these, there are several ways to do it. I've chosen the method that uses the least dice, uses only blank d6's when possible, and/or I just prefer. Blank d20's might be easier to find than blank d10's, so you can just use a blank d20 whenever I call for a blank d10. Since some of the larger dice build upon the smaller ones, for brevity I just refer to smaller non-standard dice when necessary.
Chessex sells some blank dice that are offered by Koplow.
Here's the list:
- d1: anything
- d2: d6 (1,1,1,2,2,2)
- d3: d6 (1,1,2,2,3,3)
- d4: available
- d5: d10 (1,1,2,2,3,3,4,4,5,5)
- d6: available
- d7: See below
- d8: available
- d9: d3 + d6 (0,0,3,3,6,6)
- d10: available
- d11:
- d12: available
- d13: See below
- d14: See below
- d15: d5 + d6 (0,0,5,5,10,10)
- d16: d8 + d6 (0,0,0,8,8,8)
- d17: See below
- d18: d6 + d6 (0,0,6,6,12,12)
- d19:
- d20: available
- d21: See below
- d22:
- d23:
- d24: d8 + d6 (0,0,8,8,16,16)
- d25: d5 + d10 (0,0,5,5,10,10,15,15,20,20)
- d26: See below
- d27: d9 + d6 (0,0,9,9,18,18)
- d28: See below
- d29:
- d30: semi-available [d10 + d6 (0,0,10,10,20,20)]
d7 Notes[edit | edit source]
There are d7's around if you can find them. They are said to roll fair, with the length-width ratio having been optimized for randomness, but I haven't seen any tests (check them out at http://www.multimania.com/arjan/pip07.htm). You might be able to get these from http://www.brsnasis.com/vendor/catGMS.htm, but I think they're out of stock. Their source, who is retired, is:
Lou Zocchi Gamescience 7604 Newton Dr, N. Biloxi MS 39532 phone 228 392 4177
However, it is possible to make home-made fair rolling 7-sided dice spinners by cutting a heptagon out of board and placing a rod through the center (you can do this for any # of sides - the internal angles of an n-sided polygon are 180(n-2)/n) (take a look at a 3-sided spinner http://beta.content.communities.msn.co.uk/DiceManiacsClubakaTheRandomFandom/ alexandersdice.msnw?action=ShowPhoto&PhotoID=105).
If you do have a d7, you can make d14's [d7 + d6 (0,0,0,7,7,7)], d21's [d7 + d6 (0,0,7,7,14,14)], and d28's [(d7 + d20 (0,0,0,0,0,7,7,7,7,7,14,14,14,14,14,21,21,21,21,21)].
d14 Notes[edit | edit source]
Also, I've seen a few d14's around (http://beta.content.communities.msn.co.uk/DiceManiacsClubakaTheRandomFandom/ kevincooksuncommonsideddice.msnw?action=ShowPhoto&PhotoID=2281;
http://members.aol.com/dicetalk/polymor2.htm;
http://beta.content.communities.msn.co.uk/DiceManiacsClubakaTheRandomFandom/ nicksdice.msnw?action=ShowPhoto&PhotoID=111) -
the first one may roll fair,but none of these have been mass-produced as far as I know.
d26 Notes[edit | edit source]
Gamescience made blank d26's
http://beta.content.communities.msn.co.uk/DiceManiacsClubakaTheRandomFandom/ nicksdice.msnw?action=ShowPhoto&PhotoID=164),
which would also provide you with d13's, but I don't think they roll fair.
Also, check out http://members.aol.com/dicetalk/polyh6.htm. With large dipyramids and trapezohedra, fair rolling dice of all even sizes (and thus all odd sizes with proper numbering) are possible - maybe some company will get around to making them.
There - with a bunch of blank d6's and some d20's, you should be able to fulfill all your swing die needs. In the 1-20 range (where most BM swing's fall within), there's only one gap greater than 1 die (d12 to d15). So go and beat people up now that you can optimize your swing die choice.
d34 Notes[edit | edit source]
d34's are semi-available, but not as blanks. Just subtract 17 whenever you roll >17. You can get them for $3.00 each at http://www.chessex.com/Special_d34.htm