This weekend Activision and Infinity Ward are kicking off the 'Game for Good' initiative, two days of Modern Warfare 2 gaming designed to raise money for the War Child charity.
The initiative is being organised with the help of GAME and Xbox Live and all you have to do to take part is play Call of Duty: Modern Warfare 2 online on the 5th and 6th of December (that's this weekend).
If more than 600,000 UK users get their Modern Warfare on, the War Child charity will receive a donation of £150,000, says Activision. An extra £25,000 will be donated for every 100,000 users after that, up to a maximum total of £250,000.
Microsoft is supporting the initiative by making Xbox Live Gold membership free for the weekend, while Game will support War Child by selling wristbands in store.
For more information and to show your support visit the Game for Good Facebook page.