BattleForge Play4Free

Battle Forge is :

BattleForge is a next-gen real time strategy game, in which you fight epic battles against evil along with your friends. What makes BattleForge special is that you can assemble your army yourself: the units, buildings and spells in BattleForge are represented by collectible cards that you can trade with other players.

and Battle Forge Play4Free:

The BattleForge Play4Free Client, which you can download here, offers you complete access to all areas and functionality of the game, including all content updates (new PvP maps, Renegade Campaign) made available since release. the  game is  very very good and you have fun