Hearthstone's latest addition has been announced, coming spring 2016: Standard format.
The coming update to Hearthstone will see the addition of two game formats: Wild and Standard. While Wild format will maintain the previous rules of Hearthstone, Standard will add new ongoing restrictions to which cards can be used, aiming to create a fresher and more focused Hearthstone experience.
Games played in Standard format will include only cards from card sets released in the current or previous calendar year, as well as the Basic and Classic sets. Cards from other sets will not be available in decks used in Standard matches, and cannot be brought into play through effects such as Piloted Shredder or Unstable Portal. The focus for balanced and competitive play, Standard format will be used for all official tournaments going forward, including the Hearthstone World Championship.
Standard format will also affect the availability of adventures and card packs, as well as crafting and disenchanting of cards from adventures. Card packs from Wild expansions will no longer be available from the Shop, and will no longer be granted as rewards. Wild adventures will also not be available for purchase through the Shop, although players who have already unlocked at least one wing of a Wild adventure will be able to unlock the others with gold. Instead, players will be able to craft and disenchant these cards for regular Arcane Dust amounts, including those from adventures.