Tough Luck Skull

The Tough Luck Skull is found in Tsavo Highway.

Directions: Note:This is the first time you come across a highway

 Keep battling through to the point where you must fight a group of Brutes, two of which are using Choppers. Kill all the enemies, destroy the shield, then continue through until you reach a long, winding bridge. At this point a Covenant Battle Cruiser should fly overhead. To your left you will see a series of yellow ladders. Go to the very last one. If you receive a regenerator at the top, you will know it is the correct ladder. Jump over or around the large metal bar, then turn to the left. Look down and you will see a large, black support below you. Jump down onto it. Walk along to the end of the support, then turn to the left again. Finally,you should be able to see the skull on a cliff across a gap. Jump across the gap, and get the skull. 

Note: You can get back to the highway. If you jump back onto the pillar you can carefully walk around the ledge until you reach the grassed area, jump off and up the hill to your right and you will be back on the highway to continue on your way! Alternatively, the player can simply return to the previous checkpoint - though you don't keep the skull, the achievement remains.

Icon: A skull marked with a three-leafed clover.

Effect: Enemies dodge grenades, needles, and vehicle assaults with a far greater success rate. However, plasma and spike grenade sticks are still possible at close range, and from behind.

Note: Does not affect Hunters or Ranged Pure Forms