The world of the Crucible is pushed and pulled by constant twists and turns, but a great change is coming—unlike anything we’ve seen before. A vault containing mysterious dark æmber has been opened, causing strange and unknowable transformations. While each House must decide to condemn or enjoy the dark æmber mutations, one thing is certain: KeyForge will never be the same! The KeyForge cardpool grows and expands once more with Mass Mutation, giving you access to billions upon billions more completely unique decks—decks with their own strategies and tactics that only you can truly master. Drawing from a cardpool of 422 cards, Mass Mutation brings over 250 brand-new cards to your decks, and with the introduction of dark æmber, mutation runs rampant. You’ll find strange new versions of familiar characters, massive creatures that stretch across more than one card, and the triumphant return of House Sanctum. Each Mass Mutation Archon Deck contains a single, ready-to-play 36-card deck, bringing together three of the diverse Houses of the Crucible into a single deck—featuring its own mix of cards and unique from every other Archon Deck in existence.