LASO Guide: The 17 Skulls & MYTHIC
Legendary All Skulls On — what's actually on, and how to survive it
LASO in Campaign Evolved is NOT all 42 skulls. Officially, LASO (also called Mythic difficulty) uses a fixed set of 17 skulls- with so many skulls now in the game, "All Skulls On" refers to an established list, not everything you've collected. Fun/bonus skulls like Bandana (infinite ammo), Acrophobia (flying), and Perspective (third person) are excluded.
How to Unlock LASO
- Find all 17 LASO skulls hidden in the campaign (skulls are spread across all 13 missions, 3 per mission for the 39 hidden ones).
- Once you have all 17, a "PLAY LASO" option appears in both the Campaign and Campaign Remix menus.
- Start the run: difficulty is locked to Legendary and all 17 skulls stay active for the entire playthrough - no partial selection.
The Official 17 LASO Skulls
| Skull | Effect |
|---|---|
| Iron | Solo: death restarts the mission. Co-op: death returns the team to the last checkpoint |
| Black Eye | Shields only recharge when you melee enemies |
| Fog | Motion tracker disabled |
| Famine | Weapons dropped by enemies carry half ammo |
| Thunderstorm | Enemies are upgraded to higher ranks |
| Mythic | Enemies have increased health |
| Grunt Birthday Party | Headshot Grunts explode in celebration |
| IWHBYD | Rare dialogue lines play more often |
| Boom | Explosion radius doubled (yours and theirs) |
| Eye Patch | All auto-aim disabled |
| Grunt Funeral | Dead Grunts detonate in a plasma blast |
| Malfunction | A random HUD element disappears each respawn |
| That's just… Wrong | Enemy awareness sharply increased |
| Speed Limit | Sprint disabled |
| Pop | Shooting Flood weak points makes them explode |
| Temperamental | Allies turn hostile faster after friendly fire |
| Johnny Ammo Seed | Reloading discards the remaining magazine |
Achievements & Rules
- MYTHIC - complete the entire campaign in LASO. 50 Gamerscore on Xbox, gold trophy on PS5, same-named achievement on Steam.
- Difficulty Modifiers block it. Officially, enabling any Difficulty Modifier preset prevents MYTHIC (and 10 other advanced achievements). In co-op, everyfireteam member must have modifiers off. Early-access players reported an exploit where modifiers didn't block achievements - assume it will be patched and don't build your run around it.
- Related skull-collection achievements: Cranial (first skull), Making a Necklace (22 skulls), Headhunter (all 39 hidden skulls).
Survival Tips from Early Access
Early Access opened July 23, so these are hard-won lessons from the first LASO runners (community-reported):
The Johnson problem
The deadliest interaction is Grunt Funeral + Temperamental: a dead Grunt's plasma blast kills a charging ally like Sgt. Johnson, the game blames you, and allies turn permanently hostile - with respawning Marines, that can end a run. Keep distance from allies when Grunts die.
Leave one enemy alive
If allies do turn hostile, leave one Grunt or Jackal alive and run - allies re-engage the enemy instead of you. Pausing and reloading the checkpoint the moment you die also saves runs.
Co-op softens Iron
Solo, Iron restarts the whole mission on death. In co-op, death only sends the team back to the last checkpoint - which makes a 4-player LASO run the forgiving route (expect hours per mission and a lot of communication).
Play it more conservatively than classic CE
Veterans report Legendary hits harder than the 2001 original - Elite melees are faster and player weapons feel weaker. Fight at range, abuse Black Eye melees on Grunts only when safe, and never reload early with Johnny Ammo Seed active.
Q: Which skulls are on in LASO in Halo: Campaign Evolved?
A: Officially, LASO uses 17 specific skulls - not all 42. The list: Iron, Black Eye, Fog, Famine, Thunderstorm, Mythic, Grunt Birthday Party, IWHBYD, Boom, Eye Patch, Grunt Funeral, Malfunction, That's just… Wrong, Speed Limit, Pop, Temperamental, and Johnny Ammo Seed.
Q: How do I unlock LASO?
A: Find all 17 LASO skulls in the campaign. Once collected, a PLAY LASO option appears in both the Campaign and Campaign Remix menus. All 17 skulls stay forced on for the entire run.
Q: What do you get for beating LASO?
A: The MYTHIC achievement (50G on Xbox, a gold trophy on PS5, same-named achievement on Steam) for completing the full campaign in LASO mode.
Q: Can I use Difficulty Modifiers during LASO?
A: Officially no - using Difficulty Modifier presets blocks the MYTHIC achievement, and in co-op every fireteam member must have them off. Players have reported a bug where modifiers did not block it, but treat that as an exploit that can be patched at any time.
Sources: official Halo Support LASO guide, Collectibles guide, and Difficulty Settings pages (support.halowaypoint.com); Halo Waypoint "Skulls & Campaign Remix" blog (June 10, 2026); early-access reports from r/halo and Steam discussions (July 23-27, 2026), labeled as community-reported. Last updated July 27, 2026.