Playable Sim

A playable Sim is a Sim which belongs to the active household, or in a broader sense any Sim belonging to a household; that is a Sim which is not an NPC.

In The Sims 2, The Sims 3, and The Sims 4 most NPCs can be made into playable Sims by moving them into a household. In The Sims, it can only be done with townies. However, doing it runs the risk of triggering the Urban Renewal Loop, unless Makin' Magic or a compilation containing it is installed.

Some Sims can live in a household without being playable, such as butlers in The Sims 3: Late Night and roommates in The Sims 2: Apartment Life.