The merc compound trains mercenaries hired in story mode with credits. The mercenaries are hired instantly at a mineral and vespene cost, at which point that unit type is put on a cooldown timer before it can be hired again. (Ground units descend via drop pod.) There is a limit to how many teams of mercenaries can be hired in each mission, and each team comes with a preset number of members. For example, the War Pigs can be hired three times and deploy in groups of four, while the Dusk Wings can be hired twice and come in pairs. Once the player receives access to mercenaries they begin every mission where they possess a base with a merc compound already built alongside their other structures.
|Fire Suppression System|
All structures repair themselves to 50% life. All structure fires are automatically put out.
|Terran Units and Structures of StarCraft II|