Halo: Campaign Evolved will include 42 skulls — see the full list here

There’s a skull in Halo: Campaign Evolved that doubles the size of explosions. There’s another that significantly reduces the mass of objects. A third gives you unlimited grenades. If you activate them all at once, you can turn Master Chief into a literal walking tank, launching everything you see (including, often, yourself) into the stratosphere. Halo: Campaign Evolved features so many skulls that, according to the developers at Halo Studios, you can create more than 4 trillion combinations of skull modifiers.

I haven’t checked the math on that (wouldn’t even know how to begin), but I believe it. Skulls are a major selling point of Halo: Campaign Evolved, the July 28 remake of 2001’s Halo: Combat Evolved, which features a fully rebuilt campaign mode but will not include any competitive multiplayer. Absent a multiplayer mode, the variety in Halo: Campaign Evolved comes from skulls.

First introduced in Halo 2, skulls are in-game collectibles that have allowed players to modify gameplay. In October 2025, Polygon previously reported that Halo Studios intended for Halo Campaign Evolved to include the most in any Halo game ever. Ahead of Xbox’s June showcase, Polygon caught up with Halo Studios over video call and confirmed that Halo: Campaign Evolved’s launch version will feature a whopping 42 skulls. (Past Halo games have generally included about a dozen.)

“Just these 42 skulls alone, like mixing and matching them, [there’s] something like four trillion possible unique combinations of outcomes,” Halo Studios community director Brian Jarrard told Polygon. “But that doesn't even include my four different difficulty settings that I get to choose on top of that, or if I'm playing by myself or with up to three other friends, right? It just gets crazy. To me, that's where this goes really over the top.”

Image: Halo Studios/Xbox Game Studios

Some of those skulls are returning favorites from older Halo games. Classics like Blind (removes your HUD), Mythic (increases enemy health), and Black Eye (forces you to melee enemies to restore your shield) are still there for players seeking a challenge. IWHBYD (unlocks secret combat barks) and Grunt Birthday Party (Grunt heads go “yay!” when you land headshots) are still there for laughs. Cowbell, Boom, and Bandana are the three skulls that turn Chief into a tank. But Halo: Campaign Evolved will feature 16 brand-new skulls, many of which have fascinating effects.

The most dramatic of the new additions is Perspective, which allows you to play Halo: Campaign Evolved in third-person. For decades, Halo has always been a first-person shooter. The developers tinkered with adding various third-person modes to 2021’s Halo Infinite, but even those rolled out incrementally and didn’t even happen until years after launch. Jarrard acknowledged they were a “testing ground” of sorts.

Image: Halo Studios/Xbox Game Studios

“We saw the response to it. It resonated with people. It worked really well,” Jarrard said. “Halo has had a history of a third-person camera, as you know anyways, with some vehicles, with things like turrets, so it's not totally foreign. But Infinite kind of broke through, broke the ice, became more of a full-set feature. And then, based on that response and seeing that proof of concept, it was very early on discussed as something that the team wanted to make available in this game as well.”

Another skull, Acrophobia, is a time capsule for fans who’ve stuck with the series since 2001. You remember the good ol’ days: Cheeto-dusted fingers, can of Mountain Dew on the side, up with three friends until 2 a.m. trying to grenade-jump your way outside the bounds of campaign levels. Officially, Acrophobia is described as a modifier that “Now issue[s] rifles AND wings.” What it really does: basically removes the gravity from Master Chief, so every time you jump you launch hundreds of feet into the air. (Though this is the first time the skull is available at launch, it's not its first appearance. Acrophobia was quietly added to Halo 3 in 2020... 13 years after that game's initial release.)

Image: Halo Studios/Xbox Game Studios

In most Halo games, before you can activate a skull, you first have to find it as a hidden collectible in the campaign. There are three skulls per mission in Halo: Campaign Evolved, and according to creative director Max Szlagor, you should be able find them all in a single playthrough; you wouldn’t, for example, first need to find Acrophobia in one level, then replay a different level with it active, just so you jump outside of the normal boundary to explore for skulls. (Szlagor said this is the one skull he’d want to activate IRL.)

There are also three skulls unlocked via Campaign Remix, a mode that automatically opens up after you find at least two skulls. Reload randomizes the pre-placed weapons that appear in a level, Adaptation randomizes the enemies that appear in a level, and Armistice prevents enemy factions from fighting against each other — so don’t expect the Flood and the Covenant to go at it when that’s activated. And those randomizer skulls don’t limit you to the weapons and enemies that have traditionally shown up in Halo: Combat Evolved.

Thanks to the inclusion of three new prequel levels, the randomized presets can draw from weapons and enemies that only showed up in later Halo games. You could, for example, tee up a remixed version of "Two Towers," run into a Brute, and shoot it with your Needle Rifle.

Image: Halo Studios/Xbox Game Studios

“It’s been an idea in my head for many, many years,” said Szlagor, who worked on 2014’s Halo: The Master Chief Collection compendium of re-releases. “For me, seeing enemies you’re not supposed to see, with weapons you wouldn’t normally see there, and then even having it where they’re all fighting in ways that they didn’t fight in the past … it just really changes the experience quite a lot.”

With 42 skulls total in Halo: Campaign Evolved, Halo Studios had to make some compromises. For 22 years, the Halo community has rallied around a challenge called LASO, which stands for “legendary all skulls on” and refers to players who can complete a Halo campaign on the highest difficulty level with every available skull activated. But even the developers literally making the game couldn’t make much progress with this daunting setup. “People come back and they're like, ‘This is not even remotely viable. We can't even get past the first room of ‘Pillar of Autumn,’” Jarrard said, referring to the first level of the game.

Halo Studios declined to share which skulls will make the finalized LASO list for Campaign Evolved, but Jarrard added that, “It’s almost finalized.” And neither of the developers I spoke to ruled out the possibility that someone will inevitably run through the campaign on legendary with literally all 42 skulls activated. (“I don’t ever doubt the community,” Jarrard said.)

Image: Halo Studios/Xbox Game Studios

Whatever players attempt to do, it’s clear this is the most customizable a Halo campaign has ever been. You could activate a specific subset of skulls to make Halo: Campaign Evolved play near-identically to Halo: Combat Evolved (including the classic 60-round Assault Rifle). You could choose a few intended for hijinks, and live out your Red vs. Blue dreams. You could probably run the Campaign Remixed skulls alongside any of your favorites to result in a variation of a Halo level that no one, even the people making the game, have ever played before. Despite being a remake, thanks in part to the sheer variability these modifiers bring to the table, Halo: Campaign Evolved truly feels like new ground for the series.

“You turn on skulls, go on legendary, get three friends, might even be across three different platforms,” Jarrard said. “Now you're doing crazy stuff that's never been done before in a Halo campaign. It's pretty awesome.”

Halo: Campaign Evolved will be released on July 28 for PlayStation 5, Windows PC, and Xbox Series X. Below, see a list of all skulls in the game alongside Halo Studios' official descriptions of each one, provided exclusively to Polygon.

All skulls in Halo: Campaign Evolved

Note: All skull icons courtesy Halo Studios/Xbox Game Studios.

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