The Training Grounds is a new event (replacing Quick Battle) that resets every day, rotating between Legacy and Standard each day, with progression rewards that will quickly grant you Mana Runes after a low number of fights. You can still play as much as you want in it, but the progression rewards cap out and the amount of Mana Runes you will get from prolonged play will no longer be as high as they used to be.

Event Type: PvP
Deck Restrictions: Legacy Version and Standard Version
Rewards: Progression
Entry Cost: 60 Mana Crystals
The primary purpose of Training Grounds is to provide a place for players to test out deck ideas.

The Training Grounds fights will not feature any leaderboards or additional objectives - we want this to be a low-stress environment where you can test your decks against other opponents.