StarCraft: Brood War
StarCraft: Brood War launched in December 1998, eight months after StarCraft. The expansion continued all three race campaigns with new units for each side, added over a hundred multiplayer maps, and shipped the map editor that StarCraft had launched without.
Initially conceived to be a co-development effort with Saffire, another game developer, this project -- like all of Blizzard's external development efforts -- foundered, so we brought it back in house to finalize and release, which is another code-name for crunch time by the core Blizzard team.
With the team's efforts, notably Rob Pardo in his early years at Blizzard as a balance designer, we added many new units, then completely rebalanced the game to be a better experience than the original.
It went on to cement StarCraft's competitive scene in South Korea, where professional play expanded into televised leagues that ran for over two decades — long after StarCraft II launched.