With the new set of cards from the Journey to Un’Goro expansion there is a new keyword being released – Quest.
Keywords are the wording on cards that have an effect on the minion/spell being played. Like Inspire, Deathrattle, Battlecry, etc.
A card with an example of a Quest keyword is – Awaken the Makers.
Quests cost 1 mana and start in your opening hand. When you play them you will see an icon where the secret icons appear above your character.
Your opponent can also see your quest, so it’s not a secret.
On this Priest quest for example you need to summon 7 deathrattle minions to get the reward, which is the card Amara, Warden of Hope.
As you can see, the rewards look pretty powerful. So while it might take quite a few turns to pull off, it may be worth it.