Call of Duty: Modern Warfare 3, the best-selling anything ever,  is now free on Steam until Sunday afternoon.

With roughly 10 trillion copies sold (one for every man, child, and amoeba to ever walk the Earth), you’re probably wondering why Activision would even need to promote the game further? Presumably the company won’t be happy until Call of Duty can be plugged directly into your wallet, or perhaps the PC numbers could use a boost.

The free-to-play offering only applies to the multiplayer portion of the game, so if you’ve been waiting to teabag that snobby PC-enthusiast friend of yours, their comeuppance has arrived.

And if you don’t know what Steam is, this nifty infographic will light your path.

Submit your PC game by December 14th for free testing and be entered to win an @intel​ CORE i9 PROCESSOR worth $1000, an iBUYPOWER​ Revolt 2 Pro Z370 worth $1750, or an ASRock​ X299. ENTER & WIN: Submit your PC game to the Intel Game Dev Program