- All players start off with 800 resources.
- Players using UNSC leaders start with 30 population.
- Players using Covenant leaders start with 40 population.
- All players start at tech level 0 with no upgrades to their units.
- All players start with a basic scout unit (Warthog, Ghost , or Chopper, depending on leader).
- All units have three upgrades.
- All leader powers have three upgrades.
- Turrets have two generic upgrades (medium and large) and one specific one (anti-infantry, anti-vehicle, or anti-air).
- Warehouses and Supply Pads can be upgraded to increase your supply flow.
- UNSC reactors can be upgraded to provide two tech levels instead of one.
- The Covenant research Ages to gain tech levels.
The player has to wipe out all the enemy bases and units on the map to achieve victory. If one player loses all of his/her bases, and isn't able to build one base in one minute, the player loses.
A 60-second countdown begins when a player's final base is lost and is paused when they begin building a new one, but it doesn't reset until the base is built, so if the base is destroyed before it's completed, the countdown continues. Elephants do not count as a base, which means you can still lose, even with an Elephant training units.
This is the default gametype for all skirmish games and is the only online mode that allows party teams.
- Almost all air and ground vehicles are more powerful than infantry.
- Never send in a Scarab without support on any difficulty above Normal or any Automatic difficulty above 56. Even your strongest units will fall if they have no support. And the support should be more than your Covenant leader.
- Make sure to upgrade your primary units.
- You'll need supplies to fulfill your objective.
- Beware the rebels - they guard all unclaimed sites.
- Extra Bases are a must.
- Make use of the extra structures on the map (one population cost to garrison):