Developer Infinity Ward describes how COD4:MW's Multiplayer functionality was built from the ground up. Watch more "Behind the Scenes" content on COD4:MW's Limited Collector's Edition Bonus DVD.

Experience a taste of Call of Duty 4: Modern Warfare's Multiplayer. From Perks and User Created Classes to Weapons and Innovative Gameplay, this all-new trailer reveals how truly deep and unique this experience will be.

Download exclusive Call of Duty 4: Modern Warfare content from back-to-back Game of the Year winning developer, Infinity Ward! One of the most anticipated titles of year, Call of Duty 4: Modern Warfare delivers intense gameplay, cinematic and photo-realistic graphics, a gripping storyline and unrivaled multiplayer, sure to keep gamers on the edge of their seat for hours on end! There are no refunds for this item. For more information, see www.xbox.com/live/accounts.

The next Call of Duty, revealed. Download the Call of Duty 4: Modern Warfare reveal trailer.

Download exclusive Call of Duty 4: Modern Warfare content from back-to-back Game of the Year winning developer, Infinity Ward! One of the most anticipated titles of year, Call of Duty 4: Modern Warfare delivers intense gameplay, cinematic and photo-realistic graphics, a gripping storyline and unrivaled multiplayer, sure to keep gamers on the edge of their seat for hours on end! There are no refunds for this item. For more information, see www.xbox.com/live/accounts.

Download exclusive Call of Duty 4: Modern Warfare content from back-to-back Game of the Year winning developer, Infinity Ward! One of the most anticipated titles of year, Call of Duty 4: Modern Warfare delivers intense gameplay, cinematic and photo-realistic graphics, a gripping storyline and unrivaled multiplayer, sure to keep gamers on the edge of their seat for hours on end! There are no refunds for this item. For more information, see www.xbox.com/live/accounts.

All-new theme created by Call of Duty 4: Modern Warfare community members from www.CharlieOscarDelta.com.

Download exclusive Call of Duty 4: Modern Warfare content from back-to-back Game of the Year winning developer, Infinity Ward! One of the most anticipated titles of year, Call of Duty 4: Modern Warfare delivers intense gameplay, cinematic and photo-realistic graphics, a gripping storyline and unrivaled multiplayer, sure to keep gamers on the edge of their seat for hours on end! There are no refunds for this item. For more information, see www.xbox.com/live/accounts.

Download exclusive Call of Duty 4: Modern Warfare content from back-to-back Game of the Year winning developer, Infinity Ward! One of the most anticipated titles of year, Call of Duty 4: Modern Warfare delivers intense gameplay, cinematic and photo-realistic graphics, a gripping storyline and unrivaled multiplayer, sure to keep gamers on the edge of their seat for hours on end! There are no refunds for this item. For more information, see www.xbox.com/live/accounts.

Download exclusive Call of Duty 4: Modern Warfare content from back-to-back Game of the Year winning developer, Infinity Ward! One of the most anticipated titles of year, Call of Duty 4: Modern Warfare delivers intense gameplay, cinematic and photo-realistic graphics, a gripping storyline and unrivaled multiplayer, sure to keep gamers on the edge of their seat for hours on end! There are no refunds for this item. For more information, see www.xbox.com/live/accounts.