Escalation is a wave defense mode, similar to Call of Duty Zombie mode or Gears of War horde mode. Players can choose any character from the campaign or DLC Packs, but every character starts with a Neutron Assault Rifle. Points are gained for each kill, which can be spent on weapons, grenades, health, overshields and opening doors. Once you are killed, you can be revived by a team-mate if they get to you in time. Unfortunately for Free Xbox Live members, Escalation mode only works for Xbox gold members.