StarCraft: Brood War is the expansion pack to Blizzard Entertainment's 1998 real-time strategy phenomenon, StarCraft. Released in late 1998 for Windows and Mac, it continues the epic storyline across three new single-player campaigns, one for each race, deepening the conflict and introducing new characters. The expansion adds seven new units: the Terran medic and Valkyrie, the Zerg lurker and devourer, the Protoss corsair and dark templar (which can merge into a dark archon), plus tweaks to existing units like the carrier, Goliath, and ultralisk. Multiplayer receives a wealth of new maps and balance refinements, reinforcing the combined-arms tactical play that made competitive StarCraft legendary. Three new tilesets, desert, snow, and the dark templar homeworld, bring visual variety. Brood War is widely regarded as one of the greatest expansion packs ever released, often considered essential to the core experience.