Halo 4 skulls
From Halopedia, the Halo wiki
This article is about the gameplay modifiers in Halo 4. For other uses, see Skull.
Halo 4 skulls are game modifiers featured in Halo 4 with the appearance of a human skull. The skulls are the same from Halo: Reach. In addition, just like in Halo 3: ODST and Halo: Reach, skulls are no longer easter eggs in-game, and can also be accessed in the campaign menu without claiming them in campaign levels.
List of skulls
Weapons drop much less ammo.
Enemy resistances and weaknesses are increased. This also affects the player.
All NPCs have doubled health.
Enemies throw grenades more often.
The following missions feature scripted events that recharge the player's shields regardless:
Unlike past Halo games, the low shield beep and shield down beep sound effects are removed when the Black Eye skull is active.
Enemies always go berserk, always dive out of the way, and never flee.
Major upgrade to the capabilities of enemies. Sangheili, excluding Zealots, will always appear as Sangheili Warriors. Unggoy will always appear as Unggoy Heavies. Kig-Yar will always appear as Kig-Yar Heavies. Promethean Crawlers will always appear as Alpha Crawlers. As with previous games, specialists, such as Rangers, are not affected. Promethean Knights and Promethean Watchers are also immune to the Thunderstorm skull's effects.
Cloud / Fog
Acceleration from explosions is increased. Melee attacks also increase knockback.
Rare combat dialogue becomes more common.
Grunt Birthday Party
In the level Forerunner, the animation of the Promethean Knight leaping onto John is changed if the level is played with the Black Eye Skull on (except on Easy). In the alternate animation, the Knight shoots him after being kicked off to ensure the player's shields don't recharge after their melee.