StarCraft Wiki:Canon policy

StarCraft is a lightly developed universe, with a lot of background detail left unsketched. The universe has "grown" over time, however, with a series of novels, short stories, and other products. Sometimes these products display contradictory information, so it's necessary to develop a policy to prevent confusion.

Top Tier
The game of StarCraft trumps any other source. Material later in the game trumps material earlier in the game (so, generally, StarCraft: Brood War information trumps StarCraft information).

Note that this includes StarCraft: Enslavers, Dark Origin, and the StarCraft 64 bonus map, Resurrection IV.

Second Tier: Manuals
The material in the gaming manuals trumps any source other than game material. Occasionally the manuals disagree with the games (for instance, details of the Mutalisk's attack form). In this case, the game trumps the manual.

Third Tier: Blizzard-published fiction
Some of the Blizzard Entertainment authorized fiction is actually published by Blizzard Entertainment employees. These include StarCraft: Uprising and StarCraft: Hybrid (authored by Blizzard employee Micky Neilson) and StarCraft: Revelations (authored by Blizzard employee Chris Metzen). Blizzard Entertainment employees have access to information other authors will never see, so their information is considered more reliable. Note that StarCraft map series available on the www.battle.net site fall into this category (namely StarCraft: Loomings, StarCraft: Enslavers II, Deception and Mercenaries II).

Fourth Tier: Blizzard-authorized fiction
Fiction and gaming material authorized by Blizzard Entertainment include the remainder of the novels and the map packs "Insurrection" and "Retribution". In some cases, the material directly contradicts the game in many areas.

StarCraft: The Dark Templar Saga: Firstborn falls into this category. Christie Golden had this to say about its canonical status:

Christie Golden: "Considering the nature of some of the events that are portrayed, I can safely say that yes, Starcraft: The Dark Templar series is going to be considered canon."