Horse races are a common form of gambling in which bettors place wagers on the outcome of a competition between two or more horses. The sport dates back to a variety of ancient cultures, including Greek and Roman chariot racing and Bedouin endurance races in the Arabian desert. In modern times, horse races have become an international activity and a major source of entertainment, with a number of popular events taking place around the world. Some of these events, such as the Prix de l’Arc de Triomphe in Paris and the Kentucky Derby and Preakness Stakes in the United States, are known as classic races.

In horse races, horses compete against each other for the prize money, called a purse. The most important factor in winning a race is the ability to run faster than one’s opponents. The best way to achieve this is by training a horse for racing, and thereby improving the speed of its gaits. The rider, who is usually a man, must also have a great deal of skill to guide his mount and coax the maximum speed from it.

Aside from racing, horses are also used for breeding. Female horses, called fillies, are often bred to produce stallions, which are then trained and used for racing. A successful stallion can bring in substantial sums of money for its owner, which is why many people invest in buying and racing horses as part of their investments.

To reduce the number of injuries sustained by horses during a race, regulations are put into place that regulate the use of certain medications and supplements. These include power painkillers, sedatives and anti-inflammatories. The medications may be prescribed by a veterinarian or obtained over-the-counter.

In addition to these prescriptions, some horses are given special allowances or handicaps to improve their chances of winning. These are based on age, sex and other factors, such as previous performances. The idea is to level the playing field by reducing the amount of weight that a horse must carry during a race. For example, a two-year-old horse will carry less weight than a three-year-old, and males will be subject to sex handicaps that will result in them carrying more weight than females.

Aside from these rules, all horse races must be started from starting stalls or gates (except steeplechases, hurdle races and jump races). The exception is when a starter chooses to start a race with a flag (which requires the stewards’ permission). The stewards are charged with ensuring that all horses are adequately prepared for the race and that the horses are not being aided in any way. If the stewards find that a horse is being aided in any way, they will disqualify it from the race.