Campaign scoring

Campaign scoring, also known as a Meta-game, is an optional game feature for the campaign mode of Halo 3.

If one chooses to play a Meta-game, one plays a normal campaign mission (single player or cooperative), but progress is scored by points for notable activities. Having skulls activated increases the amount of points that you gain, as well as accuracy and kill count. Different enemies give different points as do headshots (and assumably any other kill that would be worth a medal). Betrayals will cause negative points so cooperative work will be necessary.