
H3: ODST: Find a legendary hidden music cue.
Very rare
Official Steam achievement definitions and latest reported global unlock rates, ordered from rarest to most common.
Rates and award counts were last observed on Sep 28, 2026.

H3: ODST: Find a legendary hidden music cue.
Very rare
Activate all terminals.
Very rare
Halo CE: Beat the par score on all Halo: CE levels.
Very rare
Halo CE: Finish The Silent Cartographer without shooting, grenades, melee, dying or restarting.
Very rare
Halo 2A MP: Win 10 matches on Bloodline in multiplayer.
Very rare
Halo 4: Complete all Spartan Ops chapters on Normal difficulty.
Very rare
Halo 2A MP: Get 25 kills with the Gungoose in multiplayer.
Very rare
H3: ODST: Beat par score on all Halo 3: ODST levels.
Very rare
Halo 4: Carry a UNSC weapon all the way through Forerunner on Heroic or Legendary.
Very rare
Halo 2: Find and claim all Skulls in Halo 2.
Very rare
H3: ODST: Face it.
Very rare
Halo 2: In The Oracle, find the holo-drone before the Heretic Leader activates it.
Very rare
Halo: Reach: Kill 1000 Skirmishers.
Very rare
Halo CE: Beat par time on all Halo: CE levels.
Very rare
Halo 2: Beat the par time on Gravemind.
Very rare
Halo: Reach: Flip the switches to become a Reach Racer!
Very rare
Halo 4: Beat the par time on Reclaimer.
Very rare
Halo 2: Beat the par time on Regret.
Very rare
Halo 2A MP: On Warlord, get 5 active camouflage power ups in a single game.
Very rare
Halo 4: Why are you even here?
Very rare