Reins are items of horse tack used to direct a horse (or other animal) for riding or driving. They are long straps that can be made of leather, nylon, or other materials, and attach to a bridle via either its bit or its noseband.

Use

Riding

Reins are used to give subtle commands or cues, also known as rein aids. Various commands may signal a turn, ask for a slower speed, request a halt or rein back. Rein aids are used along with leg aids, shifting of body weight, and sometimes voice commands.

Driving harness

On some types of driving harness there might be supporting rings—called terrets—which carry the reins over the animal's back. When pairs of equines are used in drawing a wagon or coach it is usual for the outer side of each pair to be connected to the reins and for the inside of the bits to be connected between the pair of horses by a short bridging strap or rope. The driver carries "four-in-hand" or "six-in-hand", being the number of reins held connecting to the same number of horses harnessed as a team.

Other uses

A single rein or rope may be attached to a halter to lead or guide a horse or packhorse. A long rein called a longe line may be used to hold a horse traveling in a circle around the handler for training and exercise purposes, or for the purpose of a clinical lameness evaluation by a veterinarian. On certain designs of headgear, a third rein may be added to the paired reins, used for leading, longeing, or other specialized or stylistic purposes. The best-known example of a third rein used in the USA is the leading rein of the mecate of the classic bosal hackamore.

Types

Types of reins include:

In popular expression

In popular culture, to rein in means to hold back, slow down, control or limit. Sometimes the eggcorn, reign in, is used. Usage of the opposing free rein dates back to Geoffrey Chaucer (1343–1400) and means to give or allow complete freedom, in action and decision, over something.