Kill 5 opponents in a row in the same game, without dying
Stick an opponent with a plasma grenade and blow them up
In a non-team game, kill 5 people by melee, from behind
Stop a Killing Spree of another player
Kill an opponent who has the Legend achievement
Kill 3 opponents within 4 seconds
Steal an occupied vehicle from an opponent and take it over
Run over, hit and kill an opponent with a vehicle
Kill 2 opponents within 4 seconds
Hit and kill an opponent with a melee attack
Kill an opponent with the sniper rifle or the beam rifle
Melee an opponent from behind
Kill the sword carrier
Kill an opponent that has the Ninja achievement
Complete The Great Journey at Normal, Heroic, or Legendary
Complete High Charity at Normal, Heroic, or Legendary
Complete Uprising at Normal, Heroic, or Legendary
Complete Gravemind at Normal, Heroic, or Legendary
Kill an enraged, berserk Brute by melee, any level, any difficulty
Complete Quarantine Zone at Normal, Heroic, or Legendary
Complete Sacred Icon at Normal, Heroic, or Legendary
Complete Regret at Normal, Heroic, or Legendary
Complete Delta Halo at Normal, Heroic, or Legendary
Complete The Oracle at Normal, Heroic, or Legendary
Complete any campaign level without dying once on Normal, Heroic, or Legendary
Complete The Arbiter at Normal, Heroic, or Legendary
Complete Metropolis at Normal, Heroic, or Legendary
Complete Outskirts at Normal, Heroic, or Legendary
Complete Cairo Station at Normal, Heroic, or Legendary
Complete the game on Normal difficulty
Complete the game on Heroic difficulty
Complete the game on Legendary difficulty
Acquire the Scarab gun on the Metropolis level, any difficulty
Kill 7 opponents from behind in a row without being spotted, any level, any difficulty
Play every available default map and stay in each game until it's over
Play every available game variant, with at least 3 other players, to the end of each game
Kill 4 opponents within 4 seconds
Kill 10 opponents in a row in the same game, without dying
Kill the sword carrier after they kill 5 or more times in a row with the sword
Blow up the Banshee in flight while manned, with grenades or the rocket launcher
Get awarded at least 8 different medals in one non-team game
