From SA Mafia Wiki
A Power Role is any non-vanilla role, including Cops, Docs, Vigilantes, and so on. Strictly speaking, all Mafia are considered Power Roles, but colloquially people only refer to town roles when talking about Power Roles. Backups are ambiguous cases, since they only have the potential to be a Power Role.
Power Roles fall into several categories. The most common power roles are:
- Investigations: Players can investigate other players to determine their role or alignment. Examples include cop, tracker, or roleblocker.
- Protection: Players can protect someone else from being killed or having a night action performed on them. Examples include doctor and jailor.
- Passive Roles: The player does not need to send out an action to use this ability. An example of a passive role is a bulletproof player.
- Killing Roles: The player has the ability to kill another player. Examples include vigilante and Serial Killers.
Typically too many Power Roles can result in a more chaotic, and thus unbalanced, game. Having a game with too many town power roles can make it difficult for the scum, as they have a high chance of being investigated, tracked, or having their night kill blocked. It also makes it easy for the town to confirm themselves and thus pick out the players who's roles don't quite match the game. Too many scum power roles, on the other hand, can make it difficult for town power roles to pick up on them or can allow the scum to kill too many players in a single night.
Power roles are encouraged to breadcrumb their roles and results if they think they can do so without being too obscure or too obvious.