Planescape: Torment is a role-playing video game developed by Black Isle Studios and published by Interplay Entertainment. Released for Microsoft Windows on December 12, 1999, the game takes place in locations from the multiverse of Planescape, a Dungeons & Dragons (D&D) fantasy campaign setting. The game's engine is a modified version of the Infinity Engine, which was used for BioWare's Baldur's Gate, a previous D&D game set in the Forgotten Realms.
Planescape: Torment is primarily story-driven, with combat not being prominently featured. The protagonist, known as The Nameless One, is a man who is immortal, but with the cost of him forgetting everything if killed. The game focuses on his journey through the city of Sigil and other planes to reclaim his memories of these previous lives, and to discover why he was made immortal in the first place. Several characters in the game may join The Nameless One on his journey; most of these characters have encountered him in the past or have been influenced by his actions in some way.
The game was not a commercial success, but received critical acclaim and has since become a cult classic.