Key rules and regulations in discus include throwing from within a designated circle, which has a diameter of 2.5 meters. The athlete must not step outside this circle during the throw, and the discus must land within the marked sector, typically at a 34.92-degree angle. The thrower has a limited time, usually about 60 seconds, to complete their throw from the time they are called. Fouls are recorded if the athlete steps out of the circle or the discus lands outside the sector.