The official website for Chivalry - Medieval Warfare announces that this melee combat game is free to play all weekend on Steam, where the game is also on sale at a 50% discount. Word is:

Sharpen your swords and steel your hearts for Chivalry: Medieval Warfare is now FREE on Steam for this weekend only! With a huge content update planned to release soon, now is the best time to get your friends into a medieval bloodbath as the game is also 50% off until Monday at 10am PST! Prove your worth as a warrior and take to the fields in search of glory. In plain English, go play right now, its completely free and already waiting for you in your Steam My Games list.