You have confused the term. High TTK means it takes significant time to kill a target. Low TTK means it takes little time to kill a target. Example: Halo has a high ttk CoD has a low ttk Destiny is in a weird place because of the mobility a high ttk usually means no kill, a ttk that is too low ends up with one side steam rolling the other. But it can be balanced out. Epic did it with Gears of War so Bungie might eventually manage to do it here.