Ready and Exhausted
From Archon Arcana - The KeyForge Wiki
Cards that are in play exist in one of two states.
Ready
Ready cards are oriented upright so that their text may be read from left to right. A ready card can be used during a player’s turn, causing it to exhaust.
Exhausted
Exhausted cards are rotated 90 degrees to the side. An exhausted card is not able to be used until it is readied by a game step or card ability. All creatures and artifacts enter play exhausted.
—KeyForge Master Rulebook v17.4 September 2024