Massacre is a perk. Perks are unlocked through contracts and Perk Amulets, and upgraded as described on the Perks page.
Levels[edit]
Level text as shown in the perk menu in game.
- I: Kills count for 1.2 streak.
- II: Kills count for 1.4 streak.
- III: Kills count for 1.6 streak.
- IV (with a Perk Pusher): Kills count for 1.7 streak.