Errata List for Alpha
First printings of this card said, ". . . can only be resurrected if another summon has been killed this turn." and " . . . Place Skeleton King on a spot where a summon has been killed this turn . . .". All the instances of the word "turn" are now "round".
The champion, Idiris, is gaining a Heavy Attack  ability due to the fact that after she runs out of Aura her primary offensive ability is useless. This will help mitigate her weaknesses during late game.
Errata List for Beta
Flight is being changed into two abilities
Starting from Beta, Flight is becoming two abilities: "Flight" and "Aerial".
Flight will allow the summon or champion to move onto occupied spots.
Aerial makes it that the only attack abilities that can target the summon or champion can only be range attack abilities.
Treacherous Terrain, Libraries of Sahas, and Inferno Pits
All three of these alterations have been changed to be triggered when a champion or summon moves on or is placed on the spot the alteration is.
Due to the speed of Concussion Punch's attack ability it is moving from a "Basic Attack " to a "Heavy Attack ".
Skeleton King is getting its second errata in two sets. Its Resurrect ability is now becoming a Resurrect Beckon ability; it functions the exact same but is now a beckon ability like every other summon.
Angel of Retribution
Both the Angel and the Companion will be getting the Range attribute added to their attack. This addition allows these summons to attack each other and future Aerial summons.
Quicksand (The Decay Ability)
The Decay Ability on Quicksand will be triggered at the end of each round instead of the beginning.