Blizzard has started to detail what exactly is coming in its next expansion for Hearthstone, Journey to Un'Goro. The big thing is that, being Un'Goro, it's going to be stuffed full of dinosaurs. While this is something we can all appreciate, there's much more to it than that.
The expansion will feature 135 cards. The new keyword that will shift up how the game plays is 'Adapt'. Some Un'Goro cards let you choose an upgrade for a card. You could choose to add a taunt to your minion, a divine shield, or +3 attack, for instance. Different minions will have different adapt triggers, and some spells will force an adaptation, too.
Another big change to the battles is that you can now have quests in a match. You pick a quest card in the first round of a battle, it then sits face up next to your hero (where your opponent can see it), and if you're able to complete the objective - summon 7 Deathrattle Minions, say - then you'll be rewarded with a very powerful minion.
With the release of Un'Goro, Blizzard will phase out three of its older expansions, in order to keep control of the meta. Blackrock Mountain, The Grand Tournament, and League of Explorers will no longer appear in the standard games.
The expansion is due out in April, but an exact date hasn't been revealed yet.