Blizzard Entertainment's military science fiction media franchise StarCraft revolves around interstellar affairs in the Koprulu Sector, a distant sector of the galaxy, with multiple species and multiple factions all vying for supremacy. The real-time strategy video game series is centered on three playable races: the Terrans, humans descended principally from exiles from Earth; the Zerg, a collective of assimilated alien species organized into a biological swarm; and the Protoss, a technologically advanced humanoid species with powerful psionic abilities. Each has distinct units, structures, technologies and methods of production, as well as its own societies and narrative campaigns. Other species important to the setting include the ancient Xel'Naga, whose actions are connected to the development of both the Protoss and Zerg, and Protoss–Zerg hybrids artificially created as part of the plans of the rogue Xel'Naga Amon.
The three playable races of StarCraft were first introduced in the 1998 title StarCraft and continued in its expansion StarCraft: Brood War and the StarCraft II trilogy. Their broad gameplay identities have remained consistent across the series: Terran forces emphasize flexibility and conventional military technology, Zerg forces rely on biological production and numbers, and Protoss armies consist primarily of technologically advanced and comparatively costly units. The races differ substantially in how they construct bases, produce armies and develop technology, while being designed to remain competitively balanced against one another.
Concept and design
Development of StarCraft began after Blizzard Entertainment's Warcraft II: Tides of Darkness. Early versions retained much of the visual appearance and technology of Warcraft II, and a version shown publicly at E3 1996 was criticized for appearing too similar to Blizzard's fantasy series. The project subsequently underwent extensive technical and visual changes. Programmer Bob Fitch rewrote much of the engine, while the artwork was redesigned using three-dimensional models that were rendered into two-dimensional sprites.
The races also changed considerably during development. Early versions of the Zerg emphasized bright blue and purple colors and more heavily insectoid designs. Protoss concept art similarly changed from an earlier blue-and-green visual scheme, while Terran units were progressively developed into the industrial forms used in the released game. Blizzard sought to make the three sides identifiable both visually and mechanically. Artist Samwise Didier described Terran structures as predominantly square and mechanical, Protoss architecture as rounded and refined, and Zerg structures as organic and spiked. The Terrans were given a worn frontier appearance, the Protoss a more elaborate technological aesthetic, and the Zerg a biological appearance based around flesh, carapaces and other organic forms. Technical limitations also influenced the designs: units were given exaggerated proportions and silhouettes so that they could be distinguished at the small scale used during play.
The different appearances accompanied separate production systems and technology trees. Blizzard spent much of development balancing the three sides while retaining abilities such as Zerg burrowing, Protoss cloaking and distinctive methods of construction. Several units and mechanics continued to change late in development; the Terran Valkyrie, for example, appeared during development, was removed before release, and returned in Brood War.
When developing StarCraft II, Blizzard also sought to preserve elements that players strongly associated with each race while replacing or redesigning others. Art director Samwise Didier said the team identified the units they considered most recognizable by polling developers: among the Zerg these included the zergling, hydralisk, ultralisk and mutalisk, while the Terran selections included the marine, siege tank and battlecruiser. Retaining such familiar units gave the designers greater freedom to introduce new ones elsewhere in the technology trees, including units such as the Protoss colossus.
Terrans The Terrans are human beings who inhabit the Koprulu sector. Most descend from people exiled from Earth during a colonization project centuries before the events of the games. The colony ships became separated from their intended destination and established settlements across several worlds, eventually developing independent governments and societies.
Society and factions Terran society is more politically fragmented than that of the other playable races. At the beginning of StarCraft, the principal power in the Koprulu sector is the Terran Confederacy, an authoritarian government centered on Tarsonis. Its opponents include the Kel-Morian Combine, the Umojan Protectorate, and the revolutionary Sons of Korhal led by Arcturus Mengsk. Mengsk launched an uprising which ultimately destroys the confederacy and replaces it with the Terran Dominion. The Dominion becomes the major Terran state through much of the series. Mengsk establishes himself as emperor after the fall of the Confederacy, while former Conferederate Marshal Jim Raynor and his raiders become one of the principal rebel groups opposing his government. StarCraft II follows the conflict between Raynor and the Dominion and later depicts Arcturus's son Valerian assuming control of the regime after his father's death.
Earth develops separately from the Koprulu colonies. By the events of Brood War, it is governed by the United Earth Directorate (UED), which dispatches an expeditionary fleet after learning of the Protoss and Zerg. The UED temporarily defeats the Dominion and gains control over a developing Zerg Overmind before being defeated by an alliance of forces in the sector.
Terran factions differ politically and visually, but generally share a common technological base. Their internal conflicts remain an important part of the series alongside the larger war with the Protoss and Zerg.
Depiction and gameplay Terran technology is based on recognizable military science fiction, including powered infantry armor, ballistic weapons, armored vehicles, aircraft and large battlecruisers. Their machinery is generally portrayed as functional and industrial rather than as technologically refined as Protoss equipment. Some humans use cybernetic augmentation, while individuals with strong psionic abilities are recruited and trained as covert operatives known as ghosts.
Terran forces combine infantry with mechanical and aerial units and are designed around flexibility. Their basic worker, the space construction vehicle, remains at a building site until construction is complete and can later repair structures and mechanical units. Biological units can be healed by specialized medical units. Several major Terran buildings are capable of lifting off and relocating, allowing bases to be rearranged or moved to new positions.
Terran armies include inexpensive infantry as well as increasingly specialized vehicles and aircraft. Their ability to repair equipment, relocate buildings and combine different unit types gives them a comparatively adaptable production and defensive system.
Zerg
The Zerg are a collective of numerous alien species incorporated into a single biological swarm. Rather than manufacturing conventional technology, the Zerg alter and breed organisms to perform specialized functions. Their units, structures and spacecraft are living creatures created through controlled mutation and assimilation.
Biology and organization The Zerg originated on Zerus, where native organisms possessed the ability to take genetic material from other lifeforms and use it to acquire new adaptations. The Xel'Naga intervened in their development and created the Overmind as a central intelligence capable of directing the species. Under the Overmind, the Zerg pursued what it regarded as genetic perfection by assimilating useful characteristics from other organisms.
Most Zerg strains are specialized descendants of species absorbed into the swarm. A creature may be altered so extensively that it bears little resemblance to its original form. Individual strains are adapted for roles such as gathering resources, aerial transport, assault, reconnaissance and command.
Under the Overmind, the Swarm was organized hierarchically. The Overmind directed Cerebrates, which in turn controlled individual broods, while Overlords and other organisms relayed control over lesser Zerg. The destruction of the Overmind disrupted this system. During Brood War, the surviving Cerebrates attempt to establish a replacement Overmind, while Sarah Kerrigan ultimately defeats them and brings most of the Swarm under her own control. In StarCraft II, Broodmothers serve as senior commanders beneath Kerrigan.
Heart of the Swarm introduces the Primal Zerg, descendants of Zerg that remained on Zerus and were never incorporated into the Overmind's Zerg Swarm. They retain the ability to acquire useful biological traits by consuming the essence of other organisms but lack the same collective command structure. Kerrigan returns to Zerus during the game and adopts aspects of their biology while rebuilding her Swarm.
Depiction and gameplay The Zerg use an entirely organic visual language. Their units draw heavily on arthropod, reptilian and other animal forms, while their buildings resemble organs or large living organisms. Most Zerg structures must be grown on creep, a layer of living biomass that spreads around their colonies.
Zerg production is centered on hatcheries and their later evolutionary forms. Hatcheries generate larvae that can develop into different unit types once the required biological structures are available. The worker unit, the drone, transforms itself into most Zerg buildings rather than constructing them externally. Units and structures slowly regenerate lost health without requiring dedicated repairs.
The ability to produce multiple units from a common pool of larvae allows a Zerg player to alter the composition of an army relatively quickly. Many basic Zerg units are inexpensive and can be fielded in large numbers, while more advanced strains provide specialized aerial, siege and support capabilities. This emphasis on numerical attacks contributed to the later use of "Zerg rush" and "zerging" as terms outside the series.
Protoss The Protoss are a humanoid species originating on the jungle world Aiur. They possess strong natural psionic abilities and technology designed in part to complement those abilities. Their history and religion are closely connected with the Xel'Naga, who encountered the early Protoss while attempting to cultivate advanced forms of life.
Society and factions Early Protoss society consisted of numerous tribes whose rivalries eventually developed into prolonged sectarian conflict. The mystic Khas discovered the psionic bond shared by the species and formulated the teachings known as the Khala. Most Protoss accepted the Khala and reorganized themselves into a caste-based civilization. The Judicator caste governed through the Conclave, the Templar served as its warrior caste, and the Khalai comprised the artisans, workers and other members of society. Tribal identities nevertheless continued within the wider Protoss civilization.