Though Call of Duty: Modern Warfare 3 has sold untold squillions of copies, evidently a few of us haven't bought it yet. Activision is opening up the shooter's multiplayer portion for everyone to play for free on PC through Steam this weekend, hoping you'll get hooked and splash out on the full game once it's over.
The free weekend will begin at 10am Pacific on Thursday, then run until 1pm on Sunday. If you have the Steam client installed, you can pre-load the multiplayer client by clicking this thing here with the words. It's a 13.75GB download, so you'll want to get that started early.
Activision has run a number of free Call of Duty weekends on PC since switching the series switched to Steamworks for DRM with Modern Warfare 2 in 2009. Steam's fancy box of tricks lets publishers easily open up games--or parts of them--for a period then restrict it to paying customers again afterwards.
Of course, you can play in the free weekend even if you have no intention of buying Modern Warfare 3 at all. Visit some exotic locations, take in the sights, conserve with the locals, and smell the napalm.