A mud ball is a golf ball that is covered in mud or dirt, which can dramatically affect the ball’s flight and trajectory. Mud balls were especially problematic at the PGA Championship in 2025. Leading up to the tournament, the Quail Hollow Club in Charlotte, North Carolina, had received a significant amount of rain, creating mud and puddles on the course. However, the PGA of America opted not to allow preferred lies (“lift, clean, and place”), in which golfers can clean a ball and move it to a nearby spot. While this decision upset some golfers, the rule is typically not used at a major golf event.