Role-playing refers to the changing of one's behavior to assume a role, either unconsciously to fill a social role, or consciously to act out an adopted role. While the Oxford English Dictionary defines roleplaying as "the changing of one's behavior to fulfill a social role", the term is used more loosely in three senses:

• To refer to the playing of roles generally such as in a theater, or educational setting;
• To refer to a wide range of games including computer role-playing games, play-by-mail games and more;
• To refer specifically to role-playing games.