The Stanley Parable is an interactive story mod built on the Source game engine, developed by Davey Wreden and released in July 2011. The game was released as a Half-Life 2 mod. Later, a stand-alone remake with new story elements was developed by Wreden and Source modeler William Pugh. The game was released in October 2013 for Microsoft Windows and December 2013 for OS X.
The player guides Stanley, the game's protagonist, through a surreal environment while the narrator delivers exposition. The player has the opportunity to make numerous decisions on which paths to take, and because at times the narrator says what Stanley will do next, the player can choose to ignore the narration and make a different choice.