Dice Pool - Mechanics

Mechanics

In most RPG systems, most non-trivial actions require dice rolls. Most RPGs roll a fixed number of dice, add a number to the die roll based on the character's attributes and skills, and compare the resulting number with a difficulty rating. However, in some systems the character's attributes and skills determine the number of dice to be rolled.

Dice pool systems generally use a single type of die, the most common being six- or ten-sided dice (d6s or d10s), though in some games a character's Attributes or Skills may determine the size of the dice in the pool, as well as their number (Deadlands is an example). While such games may require different sized dice for different rolls, the dice in a given pool are usually all of the same size.

The results on each die may be added together and compared to a target number (as in Over the Edge), or the player may count the number of dice which roll higher than a specified target number, and compare that to a required number of "successes" (as in early editions of Shadowrun or the Storyteller System). In systems using the latter method, the target number required for a success may be fixed (the same for every roll) or variable (assigned depending on the difficulty of a task); the number of successes required may indicate the degree of success, or a minimum number of successes may be required as another means of determining difficulty. Another variation is that a number of dice are rolled, but only some are added together (as in the "Roll and Keep" system used by Legend of the Five Rings and 7th Sea).