https://www.pcgamer.com/hearthstone-rise-of-shadows-is-live-in-north-america-eu-appears-to-be-struggling/

Hearthstone: Rise of Shadows, the new expansion set that sees some of the game's most notorious bad guys getting up to no good as The League of E.V.I.L., is now live. Which also means that the annual set rotation has happened, meaning cards from Journey to Un'Goro, Knights of the Frozen Throne, and Kobolds and Catacombs will no longer be eligible for play in the Standard Mode. 

Rise of Shadows will bring 135 new cards to the game, as well as a new type of "token" card called, appropriately, Lackeys. Lackeys don't come from packs, but are instead created by other collectible cards; they're low-cost and low-stat cards—1-Mana, 1/1—but each has a relatively powerful accompanying ability, so expect plenty of experimentation with the little critters for the first couple of days.