Many Role Playing Games (RPGs) along the lines of Dungeons and Dragons use polyhedral dice that do not have six faces but instead may have 4, 8, 10, 20, 30 even 100s of faces with numbers, spots, words or symbols.

In RPGs the dice are used to gain strength and power in specific categories. Wizardry and sorcery in ancient times may be expressed in terms of dice throws. Players take on character identities and may become elves, knights, wizards, etc.  These characters will have abilities like speed, strength and magic which can be determined by the throw of the dice.  

In Collectable Dice Games (CDGs) players must buy or collect particular dice to use against opposing players, giving them superior abilities, powers and the advantage.  Consequently, some dice are rarer than others.

These small plastic polyhedral shapes hold the key to a RPG or CDG game's course and outcome. 

There is a shorthand used by game players to express the results and the type of dice used in a game.  Read about standard dice notation for an explanation.

Polyhedral dice are usually numbered with numerals not spots.  Sometimes they are numbered more than once with the same numeral.  d20s are sometimes numbered twice with the numbers 0 - 9.  It is also possible that some numbers will be marked more frequently than others.  For example, a d6 marked 2, 3, 3, 4, 4, 5.  Dice like these are known as averaging dice.  They change the odds of particular totals being thrown and prevent extreme results.  Unscrupulous players may use crooked polyhedral dice marked twice with a particular number to give themselves better odds.

Many polyhedral dice are not marked with numbers but are marked with symbols, categories or instructional words.  These dice are usually specifically used for their own particular RPG or CDG although not always.

The geometry of these polyhedral shapes is a science in itself and has fascinated scholars and mathematicians through the ages.  Read polyhedral dice geometry if you want to learn about the mathematics and variety of these dice solids.

Polyhedral dice often come in standard sets of seven - d4, d6, d8, 2d10, d12, d20.  One d10 will be marked in tens, 0 to 90, so it can be used with the other as percentile dice (d%).  

The standard polyhedral set above is only part of the range of solid shapes used for dice.  You may come across all sorts of dice shapes and there are many patents in existence detailing interesting and new ideas and weird, exotic solid forms. 

Polyhedral dice come in a range of attractive finishes, colours and materials to appeal to a RPG or CDG gamer's aesthetic senses.  You can even find them made from real semi-precious stones and minerals.