What are dice?
Dice come in all shapes, sizes, colors. Dice are described by the number of sides. A standard 6 sided die is called a d6. Three standard 6 sided dice would be referred to as 3d6. The most common dice used in RPGs are:
d4 - A four sided die.
d6 - A six sided die.
d8 - An eight sided die.
d10 - A ten sided die. In the 80’s a d10 was a twenty sided die with the numbers 0 to 9 twice.
d12 - A twelve sided die.
d20 - A twenty sided die. In the 80’s, a d20 was a twenty sided die with the numbers 0 to 9 twice in two different colors, like black and red. Often a d20 was made from a d10 by using a marker to color in one set of the number (0 to 9) to signify they were 11 to 20.
d100 (two dice) - Are used to get a number from 1 to 100. Today there are special d10 with the numbers 00, 10, 20, 30, ... 90. You roll one of these and a regular d10 to get a number from 1 (00 + 1) to 100 (00 + 0), the dice are really 0 to 99, the zero is treated as 100. In the 80’s, you used 2d10 (d20) of different colors and used one as the 10 factor die and the other was the ones factor to generate a number from 0 to 99. PER the D&D 5e Players Handbook, page 6, 00 + 0 is 100.
dF - Fudge dice are made for the Fudge roleplaying game. A fudge die contains two sides with a plus sign (+), which represent +1; two sides that are blank, which represent 0; and two sides with a minus sign (-), which represent -1. A Fudge die is functionally a three sided die (d3). While most d3s have sides 1,2 and 3, a dF has sides of -1, 0, and +1 - equivalent to a d3-2.
Special Dice - There are all kinds of special dice for PRG. Here are some examples.
NPC Mood Dice
Random dungeon creation dice
Random trap dice
Hit Location dice
A Standard set of RPG Dice includes seven dice; d4, d6, d8, d10, d10 (ten factor), d12 and d20.