Hearthstone is a card game from Blizzard. The first thing that comes to mind when you see this game is Magic: The Gathering. True, there are almost more differences between them than similarities. First and most obvious: Magic is intended to be played on the table, and Hearthstone is difficult to imagine as a board game. Moreover, Heartstone has the slogan "Easy to play, hard to master". And indeed: it is very easy to start playing: the game is free, the rules are clear and simple. Of course, in order to achieve any results, you will have to either spend real money or a lot of time in the game. Additional cards cost gold, which can only be earned through victories or daily quests.
Another feature of Hearthstone is the design: the whole Warcraftuniverse is behind the game, so all the cards are characters you know, with familiar lines and corresponding effects.
It is also worth noting that Hearthstone has very quickly become an eSports discipline, so there is an incentive to start playing right now.