HeathStone: Heroes of Warcraft, a new free-to-play collectible card game, has been announced at PAX East by Blizzard.

The game has been created by a small team of just 15 developers and hasn't required the lengthy development period of Blizzard's triple-A titles.

In the game players will take control of heroes from nine World of Warcraft classes.

There are over 300 cards in the game, with five offered in each pack. There are many different types of card, some obviously more desirable than others. Whilst buying packs appears to be where Blizzard will make its money, it will also be possible to earn packs through in-game achievements.

It's all built on a 3D engine too, meaning card battling has been enhanced with a fully 3D board and a host of visual effects to make the action more entertaining - even to those just watching.

The game will be released first on PC and Mac, followed shortly after on iPad.

You can sign up to take part in the beta here.