History of gaming dice: origins, d6 and polyhedral dice
Randomizing objects with ancient origins
Dice and other random-draw objects have existed for thousands of years. Ancient examples have been found at archaeological sites, with shapes and uses that do not always match modern dice.
Their exact origin cannot easily be assigned to a single region. Different civilizations used similar objects for games, chance and divination.
Dice games were already widespread in antiquity, including in the Roman world, where play could be regulated or prohibited depending on the period and context.
Once strongly associated with chance and wagering, dice are now common in board games and dice games, probability exercises and tabletop RPGs using d4, d6, d8, d10, d12 or d20.
For more background on the history of dice, see Wikipedia.
From d6 to polyhedral dice: the main types of dice
Many forms appeared across cultures, including cubic dice, polyhedral dice, numbered spinning tops and other randomizing objects.
The six-sided cube, or d6, remains the most familiar format. Its faces are numbered 1 through 6 and it appears in countless board games.
Tabletop role-playing games popularized other solids such as d4, d8, d10, d12, d20 and sometimes d100. The notation simply indicates the number of faces, letting game rules use different result ranges.