10 Hardest Video Game Achievements To Unlock
3. LASO Master - Halo: The Master Chief Collection
The Achievement: "Complete each individual game-specific LASO playlist for every Halo game."
As wonderful as Halo's Master Chief Collection is, its "LASO Master" achievement is what gamers' nightmares are made of.
LASO stands for "Legendary, all skulls on," meaning that players need to beat all of the MCC campaigns - that's all four main Halo games, plus ODST and Reach - on Legendary difficulty with the difficulty-accentuating skulls turned on.
Skulls basically give enemy combatants a major edge during engagements with significantly boosted health while your own capabilities are majorly reduced, such as the UI being removed and ammo rationed.
Oh, and if you die while playing solo you have to start the mission again, so for the sake of your sanity it's strongly recommend to tackle this one with at least one friend - or better still, don't bother at all.
The sheer level of difficulty makes this extremely time consuming, enough that only 0.02% of Xbox players have the achievement.