From Liquipedia Hearthstone Wiki
Standard is a new format in Play mode that allows players to go head-to-head using only the most recently released Hearthstone cards. You’ll play Standard using a deck built solely from a pool of cards that were released in the current and previous calendar year, along with a core foundation of the Basic and Classic card sets (which will always be valid for Standard). You’ll be matched against other players who are also using Standard decks.
Standard promises a fresher Hearthstone experience!
Theme of the Year
|2016||Kraken||(2016-04-26 - 2017-??-??)|