Halo 3: ODST will get a new mode called Firefight. Firefight introduces a new co-op multiplayer mode where you, and four other players can battle wave after wave of endless enemies. You will be able to unlock different places for Firefight as you play through the Campaign mode. to complete 1 round of firefight you will have to satnd and fight through five waves of enemies. When you complete a round of firefight a skull will be activated, and just like in Halo 3 the rule will change. The more rounds you complete, the more skulls will be activated. At the end of a round Health Packs will appear, These will be used for healing the ODST’s health since they dont regenerate their health like Master Cheif.