Being the fourth profile on the polyhedral life our favorite dice. This week: The d10.d10 isn't like the other dice. While it can serve the function of hit die and damage as well as any other, it can also complete itself by being rolled with a twin. As soon as RuneQuest came out with percentile-based skills, d10 achieved its true destiny.
Real name: Pentagonal trapezohedron AKA deltohedron AKA decahedron
Nickname: Percentile dice. To prevent players from cheating by "switching" the color of their tens and singles, manufacturers offer true percentile pairs:
Uses: Rolling Fighter hit points. Longsword damage. Skills in RuneQuest, Call of Cthulhu, etc. DCHeroes/MEGS' main engine. World of Darkness. Cyborg Commando's d10x. 7th Sea/Lot5R's Roll and Keep. White Wolf. I.C.E.'s many many many tables (and a shout-out to MERP fans!).
Beloved because: Legend of the 5 Rings' exploding 10. The baddest doubles in DCH. Easy to spin. Required for when you want to roll on a huge number of possible outcomes or very specific odds.
Hated because: The ominous "0" that represents the number 10. I.C.E.'s many many many tables. Dice sets that don't have two d10s of different colors.
Biggest rival: Zocchihedron, the so-called 100-sided dice.