Planescape: Torment was developed by Black Isle Studios and released on December 12, 1999. The game takes place in the Advanced Dungeons & Dragons Planescape campaign setting, and uses BioWare's Infinity Engine (the same engine used in Baldur's Gate and several other related RPGs). Unlike those games, Torment focuses heavily on NPC interaction and dialogue, although it does also include combat.

Players follow the story of the Nameless One, a heavily scarred immortal who has lost his memory. With the aid of a floating skull named Morte, he must rediscover his past and the secrets behind his immortality.

The game has been listed in Gamespy's "Hall of Fame" as well as Gamespot's "Greatest Games of All Time".