Steam brings us its latest Weekend Special in the form of Left 4 Dead at 50% off. So if you have been weighing your options of helping fight off the Zombie Horde with your friends, now is the time to make that decision to join in the fun. From today, Feb 13th, through Monday, Feb 16th, you can get your digital mitts on a copy of Left 4 Dead at only $25.

Unfortunately, this deal doesn't apply to the Left 4 Dead Four Pack or the Valve Pack in any form of discount, but still a wonderful deal to be had by all. Now get out there and start killing some zombie scum.