Reining is a judged event designed to show the athletic ability of a ranch type horse within the confines of a show arena. In NRHA competition, contestants are required to run one of thirteen approved patterns, included in the NRHA Handbook.
Each pattern includes small slow circles, large fast circles, flying lead changes, roll backs over the hocks, 360 degree spins done in place, and exciting sliding stops that are the hallmark of the reining horse.
Reining requires the horse to be responsive and in tune with its rider. As the rider aids the horse, it should not be easily seen by judges and spectators and all movements should appear as fluid and natural as possible. Reining judges the horse on its ability to perform a set pattern of movements. In judging the execution of the pattern, credit is given for smoothness, finesse, attitude, quickness and authority of performing various maneuvers, while using controlled speed which raises the difficulty level and makes him more exciting and pleasing to watch to an audience. A good reining horse should be willingly guided or controlled without apparent resistance.