Arma 3, Bohemia Interactive's answer to Call of Duty, has been made free over the weekend.
This is in celebration of their 'Make Arma Not War' contest, which is set to end soon as Bohemia is already going through the entries. You can choose to just play the game for free right now. Bohemia has also opened up options for you to buy either the standard or digital deluxe edition for half off. Bear in mind that this does not include the upgrade from the standard to deluxe edtions, or the DLC bundles.
Arma 3 distinguishes itself in the crowded military shooter market with a focus on realism. It is also the base game from which the DayZ mod was originally made from. Make no mistake; Arma 3 is a worthwhile game on its own terms, even if it is by the numbers.
You can play or buy Arma 3 half off on Steam here.