With the guidance of Serina, a spirited artificial intelligence (AI) persona, gamers will direct legions of UNSC soldiers, Warthogs, Scorpions and more, each group having its own strengths and uses in battle. Adventurous commanders can also call upon ancient Forerunner technology, if they are fortunate enough to find it hidden throughout the battlefield.

Covenant forces are also waiting for players to lead them into battle in multiplayer skirmishes via the New Xbox Experience. Call upon an arsenal of new and familiar Covenant units such as Grunts, Elites, Ghosts and even Scarabs to defeat foes on the battlefield. Strategic-minded players who react well under pressure will emerge victorious.