In campaign, leaders can be revived if they are killed in action, as long as the life bar is halfway full. Hero units are more adept to fighting, possessing more armor for protection against enemy units, as well as access to unique weaponry and 'special abilities' (such as 'Rage mode' for the Arbiter or special upgrades like the ODSTs for Captain Cutter).

The Covenant have leaders that double as in-game units, while the UNSC leader powers vary greatly and are numerous. Leaders offer a varied experience in Halo Wars' multiplayer aspects, bringing unique abilities into the fray.