Polygon has updated its guide with the locations of every skull in Halo: Campaign Evolved, completing coverage of the game’s collectible gameplay modifiers. The additions matter for players pursuing the demanding Legendary All Skulls On challenge or the Headhunter achievement/trophy, both of which require collecting the full set.

– There are 42 skulls in total: 39 hidden across 13 levels, with three in each, and three unlocked automatically after finding two.
– The collection includes 26 returning skulls and 16 new modifiers.
– Skulls can be enabled through level select before starting a campaign or individual mission.
– Their effects range from infinite ammunition and stronger enemies to disabled HUD elements, altered weapon behaviour and comic Grunt effects.
– The guide’s update is dated 30 July.