Modern Warfare 2 Challenges Here is a list of all the challenges available in Modern Warfare 2′s multiplayer. Challenge How To Complete Unlocks XP Reward Marksman I 10 kills Grenade Launcher 250 Marksman II 25 kills Red Dot Sight 1000 Marksman III 75 kills Silencer 2000 Marksman IV 150 kills ACOG Scope 5000 Marksman V [...]