Those nutty Hearthstone cards from BlizzCon are being added to Arena soon

On the heels of Hearthstone's Year of the Raven announcement, Blizzard is making huge changes to the game's Arena format, chief among them a new rarity system for drafting. 

Currently, when you draft cards in Arena, you pick between three cards of the same rarity. But as of upcoming update 10.4, you'll choose between three cards of different rarities but comparable power levels. 

Commons, Rares and Epics will still appear at roughly the same rate, but alongside different rarities of similar value. Picks one, 10, 20 and 30 will still guarantee a Rare card or better, and Legendaries will also be matched up according to power level.

Additionally, the update will make class cards, spells, and weapons appear in draft picks more often, and make bad cards appear less often. Cards from the most recent set will also no longer appear inordinately frequently, as the modifier behind their abundance will be temporarily disabled. 

As lead systems designer Kris Zierhut explained in today's designer insights video, these changes are intended to create more interesting draft choices. In the same vein, each class is getting a new unique card which can only be played in Arena. Have a look at the whole set: 

As previously reported, the Year of the Raven is making some big additions of its own, including easier quests with better rewards, a new Druid hero, and three new expansions. And after reviewing the best community theories going around, we've got some idea as to what those expansions will look like