A neck rein is a type of indirect rein aid

Riding aids

Riding aids are the cues a rider gives to a horse to communicate what they want the animal to do. Riding aids are broken into the natural aids and the artificial aids.-Natural aids:...

. The horse

Horse

The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...

 responds to a neck rein when it has learned that a light pressure of the right rein

Rein

Reins are items of horse tack, used to direct a horse or other animal used for riding or driving. Reins can be made of leather, nylon, metal, or other materials, and attach to a bridle via either its bit or its noseband.-Use for riding:...

 against its neck on that side means for the horse to turn left, and vice versa.

The neck rein is used in both English riding

English riding

English riding is a term used to describe a form of horse riding that is seen throughout the world. There are many variations in English riding, but all feature a flat English saddle without the deep seat, high cantle or saddle horn seen on a Western saddle nor the knee pads seen on an Australian...

 and in Western riding

Western riding

Western riding is a style of horseback riding which evolved from the ranching and warfare traditions brought to the Americas by the Spanish Conquistadors, and both equipment and riding style evolved to meet the working needs of the cowboy in the American West...

, though the style differs between the disciplines.

In both disciplines, the horse should look in the direction it is going. Head tossing and turning the head to the outside of the turn are clear signs of bad training and/or faulty rider technique. Moving the hand slightly to the left brings the rein into contact on the right side of the horse's neck, and the horse learns to turn left, away from the pressure. Likewise, moving the hand to the right means for the horse to turn right. A horse that has been well trained to neck rein becomes so responsive to legs and seat that it is possible to take the bridle

Bridle

A bridle is a piece of equipment used to direct a horse. As defined in the Oxford English Dictionary, the "bridle" includes both the headstall that holds a bit that goes in the mouth of a horse, and the reins that are attached to the bit....

 off completely — a move sometime seen in non-competitive exhibitions.

Young horses are first taught to respond to a direct rein, with reins held in both of the rider's hands, turning the horse's head by tightening the rein on the side of the desired turn. The correct way to teach neck reining relies on perfecting the horse's responses to weight and leg aids while slowly using less direct rein pressure and introducing the feel of the rein against the neck as a cue. A young horse in training needs a reminder from time to time to look where it is going, but horses learn to neck rein fairly quickly, if trained properly. Occasionally trainers will use sloppy and incorrect methods such as crossing the reins under the neck or using reins with tacks or pins in them, but this poor level of horsemanship is thankfully not seen as often in western riding today as it was in years past.

When riding in the Western style

Western riding

Western riding is a style of horseback riding which evolved from the ranching and warfare traditions brought to the Americas by the Spanish Conquistadors, and both equipment and riding style evolved to meet the working needs of the cowboy in the American West...

, riders hold both reins in the left hand (if they are right-handed). This was historically so that they could hold a lariat

Lariat

Lariat can refer to:*A rope in the form of a lasso*Lariat chain, a science demonstration*A professional wrestling move, a variation of a clothesline*A genetic structure in Splicing *Double Lariat, a popular song sung by Luka Megurine...

 or other needed tool in their right hand. The reins are kept relaxed and somewhat loose. In western pleasure

Western Pleasure

Western Pleasure is a western style competition at horse shows that evaluates horses on manners and suitability of the horse for a relaxed but collected gait cadence and relatively slow speed of gait, along with calm and responsive disposition. The horse is to appear to be a "pleasure" to ride and...

 competition at horse show

Horse show

A Horse show is a judged exhibition of horses and ponies. Many different horse breeds and equestrian disciplines hold competitions worldwide, from local to the international levels. Most horse shows run from one to three days, sometimes longer for major, all-breed events or national and...

s, riders are not supposed to ever to take the slack out of the reins when neck-reining, and even cues to slow or stop must be very subtle. For working horses, a relaxed rein allows the animal freedom to move over rough terrain. There is some slack in the reins unless the rider needs to tell the horse to stop.

For polo

Polo

Polo is a team sport played on horseback in which the objective is to score goals against an opposing team. Sometimes called, "The Sport of Kings", it was highly popularized by the British. Players score by driving a small white plastic or wooden ball into the opposing team's goal using a...

 and polocrosse

Polocrosse

Polocrosse it is a team sport that is played all over the world. It is a combination of polo and lacrosse. It is played outside, on a field , on horseback. Each rider uses a cane stick to which is attached a racquet head with a loose, thread net, in which the ball is carried. The ball is made of...

 the rider holds one or two pairs of reins in one hand. Slack in the reins is not required.

In English riding

English riding

English riding is a term used to describe a form of horse riding that is seen throughout the world. There are many variations in English riding, but all feature a flat English saddle without the deep seat, high cantle or saddle horn seen on a Western saddle nor the knee pads seen on an Australian...

 and other systems where the primary means of communication is light pressure between the rider's hands and the horse's mouth, light pressure is always maintained on the bit. The neck rein in English riding is used in addition to a direct rein and reinforces certain riding aids

Riding aids

Riding aids are the cues a rider gives to a horse to communicate what they want the animal to do. Riding aids are broken into the natural aids and the artificial aids.-Natural aids:...

, particularly turns that require the horse to set back on its haunches, such as turns at high speeds when show jumping

Show jumping

Show jumping, also known as "stadium jumping," "open jumping," or "jumpers," is a member of a family of English riding equestrian events that also includes dressage, eventing, hunters, and equitation. Jumping classes commonly are seen at horse shows throughout the world, including the Olympics...

 in a timed jump-off, or in events such as Dressage

Dressage

Dressage is a competitive equestrian sport, defined by the International Equestrian Federation as "the highest expression of horse training." Competitions are held at all levels from amateur to the World Equestrian Games...

 when performing a Pirouette

Pirouette (dressage)

A Pirouette is a French word for the Ballet reference, "to whirl about."A pirouette is a two-track lateral movement asked of a horse in dressage, in which the animal makes a circle with its front end around a smaller circle made by the hind end...

. It is interesting to note, however, how many well-trained English horses seem to already know how to neck rein without being formally taught — further proof that the skill is primarily an outcome of encouraging responsiveness to the legs, weight and a light hand.