StarCraft: Brood War is the expansion pack for the award winning military science fiction, real-time strategy video game StarCraft. Released in 1998 for Windows and Mac OS, it was co-developed by Saffire and Blizzard Entertainment. The expansion pack introduced new campaigns, map tilesets, music, extra units for each race, and upgrade advancements. The campaigns continue the story from where the original StarCraft ended, with the sequel StarCraft II: Wings of Liberty continuing from the conclusion of Brood War. The expansion was released in the United States on 30 November 1998.
Brood War was critically well-received, with reviewers praising it for being developed with the care of a full game rather than as an uninspired extra. As of 31 May 2007, StarCraft and Brood War have sold almost ten million copies combined. The game is especially popular in South Korea, where professional players and teams participate in matches, earn sponsorships, and compete in televised matches.
StarCraft focuses around three distinct interstellar species: the psionic Protoss, the adaptable Terrans, and the insectoid Zerg. The game revolves around players collecting resources to construct a base, upgrade their militaries, and ultimately conquer opponents. Brood War's gameplay remains fundamentally unchanged from that of StarCraft, although it introduces fine-tuning to unit costs and some abilities for strategic and balance purposes. These changes make rushing tactics—a factor that gained some criticism in the original StarCraft—less practical. The single-player campaign has an increased difficulty; missions are no longer entirely linear, and a greater focus on strategy is needed to complete missions. In addition, the game's artificial intelligence (AI) has been augmented so that AI-controlled players are more intelligent and tends to use tactics more effectively.
Brood War introduces seven new units. Each race is given access to a unique ground unit: the Zerg can create a defensive unit that can attack from the concealment of its burrow, while the Terrans can train combat medics. The Protoss are able to produce dark templar units, a powerful cloaked melee unit only given to the player in special missions of StarCraft. Protoss players can merge two of these units to create a special spellcaster unit. Each race is also given access to a dedicated air-to-air attack unit.