Choose a House
Each KeyForge deck is composed of three different houses, which are shown on the Archon identity card. During this step, the active player chooses one of the houses on their Archon identity card to be the active house for the remainder of the turn and announces the choice to their opponent. This active house determines which cards the active player can play, discard from their hand, and use this turn.
After choosing a house, the active player has the option to take all cards in their archives and add them to their hand.
If a player controls a card that does not belong to one of the three houses on their Archon identity card, they may (if they desire) choose and activate that house during this step instead of one of the three houses in their deck.
A player cannot choose to activate a house unless it is either on their Archon identity card or they control a card that belongs to that house. If a card effect instructs a player that they must activate a house other than one in the aforementioned categories, that card effect is ignored.