A dice pool is the group of dice being rolled by a player attempting an action, and is a concept used in all of White Wolf's game systems.
Dice pools are usually determined by a character's traits, most often a combination of relevant Attribute and Ability or Skill (for the Storyteller and Storytelling systems, respectively). For example, when attempting research at the local library, the dice pool would likely be a number of dice equal to the sum of the character's Intelligence Attribute and Investigation Ability or Skill. For certain actions supernatural powers (e.g. Disciplines, Sphere or Arcanum ratings) or other Advantages or Merits (e.g. Arete, Mantle or Renown) may be used instead of one or both of the usual traits. In the Storytelling System, these are sometimes used in addition to the Attribute and Ability. Common Advantages, like Willpower, Humanity or Virtues, may also be rolled under certain circumstances, though these are rarely added to other traits.
In the Revised Storyteller System used by the Trinity games and Scion, dice pools for most tasks were pre-figured by adding together set combinations of Attribute and Ability. In all other versions of the system, the Storyteller arbitrates the most appropriate combinations, though the Storytelling System features rules which dictate the dice pools for many tasks.
In Werewolf: The Wild West, a dice pool is referred to as a fist.