| Gold Skull Locations: | | | | When activated, enemies will be of a higher rank. |
| Black Eye (Located: Crow's Nest) | | | | Tilt (Located: Cortana) |
| When activated, you will have to battle enemies with | | | | When activated, enemies will become more resilient to |
| melee tactics to regain shield energy. | | | | your attacks. |
| Catch (Located: The Storm) | | | | Tough Luck (Located: Tsavo Highway) |
| When activated, enemies will throw more grenades. | | | | When activated, enemies are skilled at getting away |
| Famine (Located: The Ark) | | | | from projectiles such as grenades. |
| When activated, dropped weapons will hold less | | | | Silver Skull Locations: |
| ammunition. | | | | Blind (Located: Sierra 117) |
| Fog (Located: Floodgate) | | | | The arms of the player and the motion tracker |
| When activated, the motion tracker disappears. | | | | disappear. |
| Iron (Located: Sierra 117) | | | | Cowbell (Located: The Ark) |
| When activated, you will be sent back to the beginning | | | | Your explosives increase in strength. |
| of the stage you're on when you die instead of to the | | | | Grunt Birthday Party (Located: Crow's Nest) |
| last checkpoint. | | | | If you manage to get a headshot on a Grunt, the Grunt |
| Mythic (Located: Halo) | | | | will explode. |
| When activated, all enemies will have twice as much | | | | I Would Have Been Your Daddy (Located: The |
| health. | | | | Covenant) |
| Thunderstorm (Located: The Covenant) | | | | Unlocks new dialogue for the campaign. |