A measure of visibility. A creature has total concealment when it is in a totally obscured square. Example: Total darkness. Contrast with heavily obscured and lightly obscured.
Published in Player's Handbook, page(s) 281, Player's Handbook 3, page(s) 223, Rules Compendium, page(s) 317, Monster Vault: Threats to the Nentir Vale, page(s) 125.