Game description: Shadow Era:
In the game there’re three types of cards: beings, spells and heroes. Fight is divided into phases during which you can get new cards from a pack, call them in the battlefield or attack enemy beings and your hero. The one who lowers the health of the enemy to zero wins. If you aren't familiar with the principles of gamblings, training is available.
The game is free but if you want to succeed in online fights, you should spend money for boosters.