Baldur's Gate: Siege of Dragonspear is an expansion for the enhanced edition of Baldur's Gate, meant to bridge the gap between it and Baldur's Gate II. It is the first new game since Icewind Dale II to use Bioware's Infinity Engine, building upon developer Beamdog's previous work with the enhanced editions of Baldur's Gate, Baldur's Gate II and Icewind Dale. Taking place after the defeat of Sarevok in the first game but before the player character's capture by Jon Irenicus in the second, Siege of Dragonspear is set around the titular city of Baldur's Gate as the player deals with a new threat to the Sword Coast.
Though not a standalone expansion, players can create a new character or import their save file from Baldur's Gate Enhanced Edition. Upon completion of Siege of Dragonspear, the player can export their save file for use in Baldur's Gate II Enhanced Edition. The expansion is claimed to clock in around 25-30 hours with more areas than both previous expansions (Tales of the Sword Coast and Throne of Bhaal).