Dec 7, 2010
From December 6 to 19, Steam users are tasked with completing online and in-game objectives, like setting up a Steam avatar and unlocking The Heavy's Iron Curtain in Poker Night at the Inventory, which can lead to winning free games. Prizes will be handed out bi-daily to lucky winners and at the end of the whole affair, Valve will hand out 100 games to three lucky Steam users.
There are also deals to be had, like cheaper copies of R.U.S.E. and even cheaper copies of Chime. Begin the hunt!
The Great Steam Treasure Hunt [Steam]