The Dice Wall of Fame: d100s, d120s, Giant d20s and Odd Shapes

Unusual dice range from true mathematical curiosities to novelty pieces. The Dice Lab’s d120 is the largest die that can be fair. The Zocchihedron packs 100 numbers into a near sphere. Giant d20s are standard dice scaled up. Only shapes where every face sits the same way relative to the others roll fair.

Why does a fair die need a special shape?

A fair die gives every number the same chance. The Dice Lab, whose dice are designed by Robert Fathauer and Henry Segerman, puts it this way: each face “should have an identical relationship to the other faces.” Mathematicians call such shapes isohedra, or face-transitive polyhedra.

The five Platonic solids qualify: the d4, d6, d8, d12 and d20 in a standard set. The d10 is a pentagonal trapezohedron, which is face-transitive too; that shape was patented as a gaming die in 1906. The Dice Lab notes that nature only allows fair shapes of this kind for certain numbers of faces.

Beyond the standard set, The Dice Lab’s dice design page lists these fair shapes:

The Dice Lab’s designers also balance the numbering, so the sums of the numbers around each corner come out even.

The d120: the largest fair die

The Dice Lab calls the d120 “the ultimate fair die allowed by Mother Nature (i.e., mathematics).” Each face is an elongated triangle. Mathematician Bob Bosch designed the numbering so that numbers around corners of the same type add up to the same sums. No fair die built on this principle can have more faces.

The Zocchihedron: a d100 that is almost a ball

Lou Zocchi introduced the Zocchihedron in 1985. It is a roughly 1.5 inch sphere with 100 flattened spots, and later versions carry internal weights.

Its fairness has been argued over for decades. According to Wikipedia’s summary, a White Dwarf test of 5,164 rolls found that results above 93 or below 8 came up less often than middle numbers. Zocchi later spread the high and low numbers more evenly. A later Gateways magazine test found that it passed a chi-square test on a soft surface. For everyday percentile rolls, the rules’ two d10 method is simpler: one die for tens, one for ones.

d3 and d2: real dice or table tricks?

Both exist as physical dice, and both have rules shortcuts.

• d3: The D&D Basic Rules say to roll a d6, divide by 2 and round up. The Dice Lab also sells a true d3 with angled end faces and a center of gravity that stops it from resting on its ends. It makes a d5 on the same idea.
• d2: The rules say to roll any die and read odd as 1, even as 2. Renegade Game Studios includes a d2 “poker style chip” in its Dungeon Crawler Carl Smush Dice Set.

The Dice Lab’s Recast 2d6 pair takes the idea further. A d3 plus a specially numbered d12 gives the same results as rolling two ordinary d6s.

Giant d20s

Oversized d20s are show pieces as much as dice. They roll the same odds as a normal d20; they are just easier to read across a table. Two examples from licensor stores:

• Critical Role’s Fey Realm Oversized d20 is 40mm, made with Everything Dice.
• Renegade Game Studios announced an Oversized Samantha D20 for Dungeon Crawler Carl at 55mm, in resin with metallic ink numbering.

For more licensed pieces, see our guide to Critical Role and licensed dice. This site is not affiliated with or endorsed by Critical Role, Renegade Game Studios or the Dungeon Crawler Carl author or publisher.

Skew dice and other odd looking fair dice

The Dice Lab’s Skew Dice look warped but keep the odds even. The maker’s line is “The dice are skewed, but the odds aren’t!” The range covers the d4, d6, d8, d10, d12 and d20, so a full skewed set can replace a standard one. Most skew dice have no mirror symmetry, so each comes in left and right handed forms.

How to shop for odd dice

Listings for unusual dice are a mixed bag, so read them closely:

1. Check the number of faces in the photos. A percentile pair of d10s is not the same thing as a single d100.
2. Look for the shape name. Geometric names such as disdyakis triacontahedron point to a fair design.
3. Check the size. Giant d20s run from desk ornament to palm sized; the listing should give millimeters.
4. Think about material. Heavy or brittle materials change how a die handles, which our dice materials guide explains.

Where odd dice fit in a collection

Nobody needs a d120 to play. The rules only call for the seven standard dice. Odd dice are for collectors, gifts and the occasional custom table. If you want a mix of dice arriving one day at a time, see our guide to dice advent calendars. To try a d100 before buying one, use our free dice roller.

Back to the main DnD dice sets guide.