expired Steam Weekend Deal - Modern Warfare 3 - $0 (Free Weekend)
This was posted 1 year 3 months 9 days ago, and might be an out-dated deal
Play the game for free until Sunday, 1 PM PST. You will need a Steam account, which will be of good use if you haven't got one.
Should expire around 8 AM EDT on Monday morning.
According to members, it's multiplayer only.