The rack is a four-beat gait with the same footfall pattern as the walk, and may be considered a faster version of the slow gait, with the footfalls occurring at rapid, even intervals. The faster a horse can rack, while staying in good form, the better. Speed, while forsaking form, is not acceptable.

The rack is executed from the slow gait and should be animated, smooth, and effortless. Major faults at the rack include:

• Pacing ~ The pace is a two-beat lateral gait where the left front/rear feet and the right front/rear feet hit the ground at the same time.
• Hitching Gait ~ Most commonly seen in the corners, where the horse tends to fall out of the rack in to the canter. As the rider tries to correct this, the horse appears to "hitch", instead of maintaining an even gait.
• Resistance ~ Resistance is often seen by the horse sticking it's nose out above the bit; refusing to flex at the poll. Other signs of resistance include an open mouth, hanging the tongue out the side of the mouth or getting it over the bit, and tail swishing.
• Loss of Form ~ Going too fast at the rack will make the horse lengthen with a straight neck, instead of being collected. Running away is the extreme of this fault.
• Tracking Sideways ~ The horse travels with the head towards the rail and the haunches in towards the center of the ring. Usually seen more often in the corners.