Always double-check

At the beginning of round three at a standard Grand Prix Trial, you deck check table 5. Elspeth’s decklist says “4 Jace, Vryn’s Prodigy”, along with a variety of other blue and black spells and lands. Her deck, however, contains 56 cards and 4 unmarked Magic Origins Checklist Cards. Her box also contains 4 Jace, Vryn’s Prodigy in clear sleeves. There are no other cards which can be represented by a checklist card on Elspeth’s decklist or in her deck. What do you do?

Judges, feel free to discuss this scenario on Judge Apps!

Many of you correctly identified this as a Tournament Error – Deck / Deck List Problem, with a penalty of Game Loss. Unmarked Origins checklist cards in a deck that can produce multiple colors of mana could feasibly be used to represent multiple cards, so they can’t be allowed. Elspeth should clearly mark those checklist cards, the players will start game 2 without sideboarding, and Elspeth will choose whether to play or draw.