A success, in the game systems used by White Wolf, represents a level of achievement when a character attempts to perform an action.
Successes are usually determined by the number of dice in a dice pool which, when rolled, equal or exceed the target number. In the Storyteller and Revised Storyteller systems, successes are negated by any 1s rolled; this may result in a botch.
Characters may score automatic successes, either instead of or in in addition to those scored on a dice roll. This represents effort in which chance is somehow avoided. Depending on the game, this could be achieved by spending a point of Willpower, or through supernatural powers, though the latter usually only applied to certain types of action. For example, the vampiric Disciplines Potence and Fortitude granted automatic successes to Strength-related tasks and rolls to soak damage, respectively. Aberrant's Mega-Attributes also granted automatic successes.
A character with sufficient mastery of the task in question can achieve basic success without rolling any dice, assuming there are favourable conditions (availability of tools, no unusual difficulties, etc.). In such cases, the task succeeds as if a single success had been rolled. This usually requires that the character's relevant dice pool equals or exceeds the target number of the roll.
Scoring a single success on a roll usually means that the character achieves the result desired, though often at a minimum level of proficiency; scoring additional successes means the character has managed a greater achievement. For example, scoring one success when researching a particular topic may indicate the researcher discovers a single relevant and useful fact; scoring multiple successes may mean she finds multiple facts, or one of greater use, or even something that is generally regarded as secret knowledge. In combat, successes usually equate directly to dice or levels of damage.
More difficult tasks, or those which require an extended period of time to achieve, may require that the character achieve multiple successes before the action is considered even minimally successful. In the Revised Storyteller System, this is equivalent to the difficulty of a task, though in the earlier Storyteller System this mechanic existed alongside the variable target number difficulty system.
Tasks which are contested between multiple characters are generally won by the character who scores the most successes when both roll for their side of the contest.
In the Storytelling System, most tasks do not have degrees of success; a single success is always sufficient for an action to succeed well. Multiple successes are only required for extended or contested actions, as penalties or bonuses are awarded by adding or subtracting dice from the dice pool, rather than by changing the number of successes required. Scoring multiple successes only grants improved results in certain circumstances, though scoring five or more successes is usually counted as a exceptional success.