Skulls in the Halo franchise are an interesting way of increasing the difficulty for the most hardcore gamers trying to play the game and the list of Halo 4 Skulls, even though not as impressive as in the past, offers many abilities (or disabilities?) to keep you happy (or unhappy?).

Either way, I have decided to create this guide to Halo 4 skulls and tell you everything about each of the skulls in the game and their effect. The good news is that you don’t have to find them or find the locations for the Halo 4 Skulls, as they are all active from the start of the game and available in the menu.

Now here are the Halo 4 skulls and their effects:

1. Black Eye Skull — Shields don’t recharge unless you melee enemies.
2. Blind Skull – The HUD and the first person arms and weapon are hidden.
3. Catch Skull — Enemies are grenade happy!
4. Cloud Skull — Motion sensor is disabled.
5. Cowbell Skull — Acceleration from explosions is increased.
6. Famine Skull — Weapons drop much less ammo.
7. Grunt Birthday Party Skull — Headshot a Grunt, HAPPY BOOM TIME!
8. Iron Skull — Restart mission on death.
9. IWHBYD Skull — Rare combat dialogue becomes more common.
10. Mythic Skull — Enemies have increased health.
11. Thunderstorm Skull — Major upgrade to the capabilities of enemies.
12. Tilt Skull — Enemy resistances and weaknesses are increased.
13. Tough Luck Skull — Enemies always go berserk, always dive out of the way, and never flee.

There is also an achievement related to the use of the Halo 4 skulls and that is the Skullduggery achievement worth 15 points and awarded for completing any mission on Heroic difficulty mode or harder with 3 or more Skulls activated. So if you want to get it, probably the easiest skulls to have active are: Famine Skull, IWHBYD Skull and Cowbell Skull.