Pace is a lateral two-beat gait. In the pace, the two legs on the same side of the horse move forward together, unlike the trot, where the two legs diagonally opposite from each other move forward together. In both the pace and the trot, two feet are always off the ground. The trot is much more common, but some horses, particularly in breeds bred for harness racing, naturally prefer to pace. Pacers are also faster than trotters on the average, though horses are raced at both gaits. Among standardbred horses, pacers breed truer than trotters – that is, trotting sires have a higher proportion of pacers among their get than pacing sires do of trotters.
A slow pace can be relatively comfortable, as the rider is lightly rocked from side to side. A slightly uneven pace that is somewhat between a pace and an amble, is the sobreandando of the Peruvian Paso. On the other hand, a slow pace is considered undesirable in an Icelandic horse, where it is called a lull or a "piggy-pace".
With one exception, a fast pace is uncomfortable for riding and very difficult to sit, because the rider is moved rapidly from side to side. The motion feels somewhat as if the rider is on a camel, another animal that naturally paces. However, a camel is much taller than a horse and so even at relatively fast speeds, a rider can follow the rocking motion of a camel. A pacing horse, being smaller and taking quicker steps, moves from side to side at a rate that becomes difficult for a rider to follow at speed, so though the gait is faster and useful for harness racing, it becomes impractical as a gait for riding at speed over long distances. However, in the case of the Icelandic horse, where the pace is known as the skeið, "flying pace" or flugskeið, it is a smooth and highly valued gait, ridden in short bursts at great speed.
A horse that paces and is not used in harness is often taught to perform some form of amble, obtained by lightly unbalancing the horse so the footfalls of the pace break up into a four beat lateral gait that is smoother to ride. A rider cannot properly post to a pacing horse because there is no diagonal gait pattern to follow, though some riders attempt to avoid jostling by rhythmically rising and sitting.