IC, acronym standing for In Character. Pronounced "Eye See" or "Ick", as opposed to OOC.

Things said by Characters in game, when you are role-playing your character.

In game things said are presumed to be in character. Some players prefer to "Quote" text said IC.

On this site, you may make IC accounts or character accounts

In the left hand column (when logged in) there are two blocks labeled Personae & Masquerade. Your initially created account is assumed to be a player account (OOC) (hopefully matching your Gamespy account you use to log into the game). You can use Personae to create (IC) character accounts corresponding to your in game characters. Masquerade can be used to quickly switch from your Player account to one of your characters and back. Please use your character accounts to join IC Groups.