i dont understand the Halo 3 Campaign Meta-game achievement?

[Patryk P]

i have achieved all the achievements except this one and i just dotn get what im suposed to do... please help me

 

[Trunk Monkeey]

well wat achivement is it explain some more so u can get better answers

but if u mean the meta games then go to campaign screen then press x and do scoreing and add skulls u need to get 15,000 or sometimes 50,000 on each level to get the achivements the skull give multipluyers and quicker u o it the better