In competition, usually competitors are asked to help as a judge. As a part of the regulations it is a must to be a judge as requested by an organizer/s or WCA Delegate. This is a means of making the competition diligently follow the schedule, to have a smooth flow of events, and more like is to live the spirit of speedcubing which is more of helping each other while having fun. We intend not to recreate the one provided by WCA in their Wiki page by the reason that this method is a standard and must come in one source for everyone to have a common knowledge. So here is the link to the WCA Wiki Page about Judging in a Competition.
