Tournament Errors & the MTR

The registered decklist is authoritative. If a player's physical deck doesn't match their list, or the list is illegal (too few cards, illegal card counts), it's a Deck/Decklist Problem, default penalty Game Loss. The fix generally corrects the deck to match the list. Players are responsible for accurately registering and presenting a legal deck.

• Tardiness — a player not seated when the round begins. After the grace period (commonly 10 minutes), the penalty is a Game Loss; longer absences lead to a drop.
• Slow Play — playing too slowly or taking excessive time. Penalty: Warning. Judges may also grant a time extension to the match to compensate for delays (including for judge calls).

Marked Cards — sleeves or cards distinguishable from the back can give hidden information. If the pattern could convey information, it's an infraction (Warning, or Game Loss if it correlates with card identities). Insufficient Randomization covers not shuffling your deck sufficiently before presenting it.

The MTR classifies information exchanged between players:

• Free information — must be answered completely and honestly if asked (e.g. life totals, number of cards in hand, cards in public zones, the name of a face-up card).
• Derived information — available to all players but requiring rules knowledge or calculation (e.g. a creature's current power, what a card does). Players must not misrepresent it, but are not obligated to volunteer it.
• Private information — known to a player but not opponents (e.g. cards in hand). Players may keep this secret and may even bluff about it, but may never lie about free or derived information.