Starcraft 2 is split into three games, each one representing a playable faction.
Protoss, Terran, and Zerg. These three distinct and powerful races will clash once again in the fast-paced real-time strategy sequel to the legendary original, StarCraft. Legions of veteran, upgraded, and brand-new unit types will do battle across the galaxy, as each faction struggles for survival.
Heart of the Swarm features The Zerg
Composed of many different species integrated into the Swarm via zerg infestation. These creatures are rapidly and selectively evolved into deadly and efficient killers to further the driving zerg imperative of achieving absolute domination. The zerg make no use of technology to create their weapons, armor, or starships. Instead, these functions are efficiently fulfilled through biological adaptation and planned mutation of the zerg strains. Even zerg buildings are in fact specialized organs within the living, growing organism of a zerg nest.