Tough Luck

Tough Luck is a gold skull featured in Halo 3, Halo 3: ODST, Halo: Reach, Halo 4, Halo 5: Guardians and Halo: Combat Evolved Anniversary as part of Halo: The Master Chief Collection. It serves to make enemies a lot more resilient, doing things like jumping out of the way of grenades and vehicles or going berserk a lot more often.
==Location==
===Halo 3===
#At the point where you must fight a group of Brutes and two Choppers, kill all the enemies, destroy the shield, and continue until you reach a long, winding bridge. At this point, a Covenant CCS-class battlecruiser should fly overhead.
#To your left, you will see a series of yellow ladders. Go to the very last one which has a Regenerator at the top.
#Jump over or around the large metal bar on the right and then turn to the left.
#Look down and you will see a large, black support below you. Jump down onto it. Note that when you jump, you have to be standing on the part of the pipe that sticks out slightly with the bolts going through it. Otherwise, you'll take too much fall damage and die.
#Walk along to the end of the support and then turn to the left again.
#Now you should be able to see the skull on a cliff across a gap. Jump across the gap on to the cliff to get the skull. 
===Halo 5: Guardians===
==Effect==
The skull in its appearances in first-person shooter Halo installments causes enemies to be a lot more resilient. Enemies will now jump away more successfully from incoming grenades and vehicles. Enemies like Hunters will go berserk and enemies like Jackals and Grunts will never flee.
==Gallery==
H3 Tough Luck Skull.png|The skull viewed in the Halo 3 campaign menu.
H3ODST Tough Luck Skull.png|The skull viewed in the Halo 3: ODST campaign menu.
HR Tough Luck Skull.png|The skull viewed in the Halo: Reach campaign menu.
H4 Tough Luck Skull.png|The skull viewed in the Halo 4 campaign menu.
H5G Tough Luck Skull.png|The skull viewed in the Halo 5: Guardians campaign menu.