OOC

From Cowboy Bebop: Space Cowboy

Out of character (sometimes abbreviated to OOC) is a phrase used in entertainment to differentiate between a person playing a fictional character|character and the character itself. When the person is being him-or-herself, he or she is said to be "out of character". The opposite, when the person is acting as the character, is "in character". Occasionally, a film, TV show, or book will break the fourth wall by having one of the characters step out of character and comment on the story or the other characters (often in a narrative way, which does not affect the story but only informs the viewer).

It may also refer to when a fictional character's behaviour is different from, and inconsistent with, how the character's personality (particularly their mental and emotional state) has been established in the past, without any apparent reason. The term does not usually apply to a character acting a certain way which is later explained in secret history, or to characters so minor little of their source personality is ever well-known. This process also applies to fan fiction where a character is acting differently from how he appeared in the story's source material.

OOC is also used in role-playing. In this case, OOC refers to things said by the author of the message, rather than by the character(s) that author is playing. The opposite of OOC is IC or "in character". It is forbidden to mix the two deliberately or accidentally as it can disrupt gameplay.