From Archon Arcana - The KeyForge Wiki
A KeyForge deck consists of 36 cards, 12 from each of three different houses. Each KeyForge deck comes with an Archon identity card with a list of the deck’s contents printed on the reverse side (known as the deck list) and may also include an additional reference card, commonly known as ”the 38th card.”
The Archon identity card and any additional reference cards that came with the deck are never shuffled into the deck during gameplay.
Cards in a player’s deck are out-of-play. Players cannot look at the contents of their decks during a game, unless allowed by a card effect.
The order of the cards in a deck must be maintained unless a card effect or game effect requires the deck to be shuffled.
—KeyForge Master Rulebook v17 April 2023