Halo: Campaign Evolved Guide to Activate 42 Skulls

Halo: Campaign Evolved packs 42 collectible Skulls spread across 13 missions, letting players apply mission-specific modifiers that can dramatically change how each run plays. Skulls are picked up during the campaign, then activated from the menu to start a selected mission with the effects you’ve unlocked.

How to activate Skulls for a new run

Once you collect a Skull, you can use it only by starting a fresh solo campaign session. From the main menu, go to Campaign, then choose New Game. This will override your current solo campaign progress, but you can select any mission and checkpoint you’ve already unlocked to resume.

After choosing a difficulty, pick the mission and rally point (checkpoint). You’ll then reach the Select Skulls screen, where you can choose which unlocked Skulls to apply. Hit Apply & Start to begin the mission with the selected modifiers.

There’s no direct way to remove Skulls once activated—using them again requires another New Game setup to change your Skull loadout.

Skulls and their effects

Below are the Skull effects listed for Halo: Campaign Evolved. Each Skull applies a specific gameplay modifier to the mission you launch with it.

Assault Rifles gain 60-round magazines.
Enables a 3rd-person camera mode.
Weapon fire drains shields, but dealing damage recharges them.
Grunts die in a blaze of plasma.
Touching the ground causes you to take damage.
Co-op death resets you to the last checkpoint.
Solo death resets the level.
UNSC vehicles cannot be damaged.
You cannot use weapons from enemy factions.
Infinite ammo and grenades.
Allows you to fly on a double jump.
Disables weapon zoom and aiming.

Additional mission modifiers

Enemies fire weapons faster and more frequently.
Reduces the physical mass of objects, letting them be displaced more easily.
Enemies have increased awareness.
Flood combatants become stronger when they reanimate.
Improves both positive and negative damage multipliers.
Hitting Flood in weak points makes them explode.
Weapons dropped by enemies contain half the ammo.
Enemies always go berserk, move out of gunfire, and never retreat.
Shields only recharge with melee attacks.
Enemies have more health.
Enemies throw and drop grenades more often.
Disables the HUD, and weapons no longer appear on screen.
Punching enemies makes them drop grenades.
Weapons reload when stowed.
Explosion radius doubles.
Upgrades the rank of most enemies.
On respawn, a random HUD element disappears.
Reloading a half-empty clip will waste ammo.
Headshots deal no extra damage.
Allies will try to kill you if you kill a friendly soldier.
Every shot costs 2 bullets.
Enemies no longer flinch when shot.
Grunt headshots make them explode into “legendary celebrations.”
Enemies killed while you are at full health grant more ammo.
Enemy types are randomized.
Unlocked with Campaign Remix after collecting 3 Skulls.
Weapon placements and spawns are randomized.
All enemy types fight together.