Call of Duty: Modern Warfare 2 developer Infinity Ward is giving fans some clarity on why it has changed up the way perks work in the new game, including making Dead Silence a Field Upgrade rather than a Perk. Recently, the Call of Duty: Modern Warfare 2 open beta began, giving players the chance to see what the game is like before they buy it later in October. During this beta test, Infinity Ward requested player feedback for Modern Warfare 2 so that it might be improved upon before release.