A judge’s primary responsibility during a tournament is to promote and maintain tournament integrity. This can be as simple as clarifying a rules question or pointing out that a player forgot to alter a life total on the scoresheet. However, situations involving procedural errors or miscommunications between players can be more complex. In these cases, and in many others, the judge will need to investigate in order to gain the information necessary to make the correct ruling.
Eric Shukan, L3
Some investigations are fairly quick and simple: the judge may ask if a land was played this turn or if any cards are known in the library (e.g., with Sensei’s Divining Top). Sometimes the judge may feel the need to acquire more detailed information that might be best obtained in a private interview and the judge might ask a player away from the table. The judge may also wish to interview spectators, in which case the spectators are required to cooperate. No matter how the investigation may proceed, remember that the judge is gathering data to make the best possible ruling or judgment based on DCI policy and protecting tournament integrity. If a player or spectator intentionally provides false information, the judge may render a ruling that is not appropriate for the situation, and then the integrity of the match and of the event would be compromised. Therefore, whether you are a player or a spectator, lying to a judge is a very serious offense.
How can you avoid this problem? Simply put: don’t lie to a judge - ever. If you are a player or a spectator involved directly in the situation tell the judge what you believe to be true when asked to do so. Everyone has his own side of a story to tell; tell it like you saw it. The judge’s job is to sort it all out, but your job is to provide the most correct information you can. If you choose to lie instead of telling the truth, especially when lying could gain you or your friend an advantage, then you are committing a very serious infraction that could result in disqualification or even lead to suspension.
Eric Shukan, L3