Blizzard's popular real-time-strategy title Starcraft II has now opened up to all players for free. Whilst this doesn't include all expansions of the game, there is still a sizeable amount of the game available.
The single-player campaign Wings of Liberty is available for free, as well as immediate access to all multiplayer units in unranked and custom modes. Players can also access ranked play after earning ten "First Wins of the Day", and are able to use all Co-op commanders up to level five.
Characters Raynor, Kerrigan and Artanis are all free to play without level cap, and players who owned Wings of Liberty before October 31st get a free copy of Heart of the Swarm.