Steam Officially Makes 4 Games 100% Free Through September 21

Steam's Free Weekend promotion is giving PC gamers a handful of co-op and multiplayer games to check out this weekend, with the current selection available from now until September 21 at 10 am PT/1 pm ET. For those unfamiliar with this specific Steam promotion, it essentially grants unfettered access to games for a limited time, but that access will end at its expiration time. The good news is usually there's a discount for anyone who wants to keep playing.