Roleplay

roleplay — Roleplaying occurs when real-life people assume the role of a character within an evolving, jointly-created story — as story usually directed by a dungeon master but to which the individual players significantly contribute over time. Generally, these players attempt to roleplay their respective characters based upon various statistics, background information, personality traits, and motivations that are recorded on a character sheet, a living document that changes over time.

Also see this article.