What is the main role of a tournament judge?

The main role of a tournament judge is to ensure that players follow the rules. Judges serve as impartial arbiters during a tournament, making sure that all participants adhere to the regulations set forth by the Magic: The Gathering tournament rules. They enforce the rules consistently and fairly, which helps maintain the integrity of the tournament environment.

Additionally, they play a crucial role in resolving disputes, providing rulings on rule interpretations, and addressing any issues that may arise during matches. This role is central because it helps create a level playing field for all participants, allowing the competition to remain fair and orderly.

The other choices do not accurately reflect the primary responsibilities of a judge. While social interaction and creating a positive atmosphere can be part of a judge's duties, they are secondary to the enforcement of rules. Playing the game for others or influencing match outcomes contradicts the impartiality and integrity expected of a tournament judge.