When you think of dice, chances are you only think about six-sided dice. After all, six-sided dice are the most commonly used dice in the world, and are the only kind of dice most people ever use. Unless you've played roleplaying games or certain tabletop games, or had a chance to use some of the alternative dice in school, the six-sided dice is probably your go-to solution for generating random numbers.
But there are actually many other shapes of dice in common use, particularly those based on the platonic solids: 4, 8, 12, and 20-sided dice. These are sometimes referred to as D&D dice since they first became well know due to the popularity of the Dungeons and Dragons role-playing game.
The four-sided dice (also known as a d4) is typically shaped like a 3-sided pyramid (with the fourth side being the base), although alternative shapes are occasionally seen.
The eight-sided dice (d8) is the shape of an octahedron.
The 12-sided dice is a dodecahedron, where each face is a regular pentagon.
The 20-sided dice, a roleplaying game staple, is an icosahedron.
Along with dice made from the five platonic solids, there are also 10-sided dice. The d10s typically are available as two different types: The type that display numbers 0-9 and those that display numbers 00-90 (also known as a percentile dice, or d%). By combining both dice in a single roll, players can obtain a percentile result from 00-100.