Hearthstone

Hearthstone is a free-to-play digital collectible card game that revolves around turn-based online 1v1 matches between two opponents, operated through Blizzard's Battle.net. Players can choose from a number of game modes, with each offering a slightly different experience. Players start the game with a substantial collection of 'basic' cards, but can gain rarer and more powerful cards through purchasing packs of additional cards, or as reward for competing in the Arena.

Players can also disenchant unwanted cards, destroying them in exchange for arcane dust, a resource which can be used to create new cards. Card packs and entry to the Arena can be purchased with gold, an in-game currency rewarded for completing randomized daily quests and winning matches, or by using real money in the in-game store.

Hearthstone is set within the Warcraft universe, with its characters, cards and locations drawing from existing lore.

(Source: Wikipedia)