For the horse and rider during competition, there are specific regulations about the tack and equipment that may and may not be used. We discuss general guidelines here; and updated rules and regulations are available in the USEF Rulebook.
In competition, horses are not permitted to wear boots or wraps on their legs nor any training devices such as a martingale or draw reins. An English style saddle is required and a dressage saddle is preferred. Normally, a plain white pad is used under the saddle but riders may use colored trim on saddle pads and have begun to use beads and other colored trim on the brow band of the bridle.
Only certain types of bits may be used in the horse’s mouth. From Training through Second Level, a simple snaffle bridle is required. A snaffle has only one rein attached to the bit. At Third and Fourth Level, the rider may choose to ride in a double bridle that has two reins and offers the rider the ability to use two bits to obtain more finesse in his ride.
Horses are turned out as neatly as the rider for dressage. The mane, or hair that runs down the neck of the horse, is normally braided. The sides of the tail may be clipped and the end of the tail cut evenly across the bottom (or banged) to add a polished look.
Riders are dressed formally in competition, traditionally with white or light colored breeches, a light-colored shirt and tie or choker with a black or navy blue colored jacket. Gloves may be white or black. For riders at the FEI levels, a shadbelly (tailcoat) is traditional. Except for very young riders, boots are black and come up to the knee.
Except for very young riders, long hair is always tied up or in a hairnet with lower level riders usually in a black velvet helmet or derby style hat and FEI level riders usually in a top hat.