Homeworld 2 shares the three-dimensional battlefield its predecessor introduced to the real-time strategy genre, and retains that game's movement system: simply right-clicking on just about any object in space will cause the selected ships to move towards it, while a fairly-intuitive system which binds the Z axis to the Shift key allows more complete control over navigation. Fighting in the interstellar void where terrain, permanent settlements and navigational landmarks are scarce, Homeworld players take a different view of tactics and strategy than do most RTS players.
Homeworld 2 features only one resource, the ubiquitous "Resource Unit" which is collected by harvester craft. These harvesters often work far away from the Mothership, with the result that strikes against an opponent's supply line can be devastating. Furthermore, RUs are the currency for both ship creation and technology research, meaning the competitors in a multiplayer match must decide carefully what to do with their limited funds.
The Mothership is capable of constructing almost every unit in the game, from the smallest Scout fighter craft to enormous Destroyers; the two exceptions are Shipyards (which according to in-game lore are built back at the home planet of Hiigara and then sent to the front lines via hyperspace) and the Battlecruiser, which is the largest combat-worthy ship in the game and can only be built at a Shipyard. The Mothership can also build Carriers, which themselves can build any ship from the Fighter, Corvette and Frigate families. The Mothership is the center of new research, though Carriers and Shipyards can build the same on-board Research Labs to take over the duties. Finally, in multiplayer matches, the Mothership (or Flagship for the Vaygr) is the only craft that cannot be rebuilt if destroyed, making it the symbolic heart of a player's fleet, even though all its functions can be carried out by surviving Carriers and Shipyards in the event of its destruction; during the single-player campaign, loss of the Mothership leads to an immediate Game Over...