For the 2011 indie game, see Sanctum (2011 video game).Sanctum is a two-player computer collectible card game, played online against human opponents. Players log into a "Game Lobby" (known as "The Gate") to find other players to challenge to a match. It runs on the Windows operating system. It was developed by Digital Addiction in 1997, and was launched to public participation on July 9, 1998.