Players are required to register their decks and sideboards (if applicable) in Competitive and Professional Rules Enforcement Level tournaments. The Head Judge may require registration in Regular Rules Enforcement Level tournaments.
Decklists are expected in Comp and Professional REL. If a Tournament Organizer wants to have decklists at Regular Rules Enforcement Level, they should make sure they inform the players as early as possible, as most won’t expect the requirement and won’t have them prepared in advance. If a Tournament Organizer decides the event is serious enough to warrant decklists at Regular Rules Enforcement Level, they may want to consider changing the Rules Enforcement Level to Competitive. Regular Rules Enforcement Level events with decklists are very rare. Typically requiring lists at Regular is in response to suspected rampant cheating.
Registered decklists record the original composition of each deck and sideboard (if applicable). Once your decklist has been accepted by a Tournament Official it may not be altered. If electronic decklists are used, decklists cannot be altered after the date and time that decklists are required to be submitted.
Altering a decklist after it has been accepted by a Tournament Official, or after the official cutoff time for electronic submission, is not allowed for various reasons: TOs/Judges may perform tournament operations on the list, players might gain additional strategic information by scouting opponents. Much like presenting a deck to an opponent is signifying a legal deck, submitting a decklist to Tournament Official (online or physically) is a declaration that the decklist is legal and final. A judge is allowed to alter the decklist when applying the fix for a Decklist Problem.
In Constructed tournaments, decklists must be submitted to a tournament official prior to the start of the tournament.
In tournaments using the IPG, not submitting your decklist prior to the announced first round of the tournament is considered Tardiness, and does upgrade. This is irrespective of byes that might have been awarded.
In Limited tournaments, decklists must be submitted prior to the start of the first round in which that player participates.
Constructed decklists need to be turned in before round 1 begins. Limited needs to be turned in before the first round the player is actually playing in begins. The rules for constructed and limited are effectively the same, however, sometimes large sealed events may have byes, and in those rare cases players with byes may have different build times. The wording for this rule allows for that possibility without explicitly mentioning byes because WoTC doesn’t have any events that award byes anymore.
Players have the right to request to see their decklist between matches. Such a request will be honored if logistically possible.
What is logistically possible is up to the judges at an event. Some event have thousands of decklists collected around the same time and trying to find one before they are organized might not be possible. If a player has alerted a judge to an error before they could gain advantage or before the event has begun, please be mindful of this information if unable to provide their list. Additionally, players will now often take a picture of their decklist once they have requested it, for their future use.
Generally, decklists are not public information and are not shared with other players during a tournament. At Professional Rules Enforcement Level tournaments (World Championship, Pro Tour, Regional Championships), copies of opponents’ decklists will be provided to players in the single-elimination playoffs.
The reason certain events share decklists is to negate the disadvantage some players gain as a result of event coverage during the Swiss portion of the tournament. In the single-elimination playoffs of limited events, the chances of your opponent gaining information about your decklist are a lot smaller. As such, we only provide decklists for constructed-format events. Star City Games Open Series have also allowed Top 8 players to view the opponents decklists due to coverage.
Note that while they have the decklist, it is considered to be notes taken outside of the game so players may only view them while in between games.
Additional information regarding digital decklists can be found in section 2.12 – Electronic Devices
