Remedies: 1. If the player’s registered decklist is illegal, the player must correct their decklist to a legal state making as little change as possible and ensure that their deck matches the newly registered deck. 2. If the player’s presented decks do not match their registered decklist but their presented decks are legal, the player must change their registered decklist to match their presented deck. 3. If the cards required to correct a decklist cannot be acquired in a timely manner, the head judge can issue a proxy.
§ 703.3.b Tournament Rules PDF (officieel)
§ 703 Tournament Errors
§ 703.3 Decklist Error [Game Loss]: A player submits a decklist for registration that contains illegal elements.