To ride shotgun is to sit in the front passenger seat when riding in a car or other vehicle. In contemporary tradition, in order to claim the seat, one must "call shotgun" according to some set of informal rules. It is a phrase commonly heard in the United States, Australia, Canada and New Zealand. Due to the influence of American popular culture it is also heard in several European countries such as Iceland, Ireland, Denmark, Norway, Sweden, The Netherlands and the United Kingdom, as well as other countries with large English-speaking populations such as South Africa and Israel. In Mexico it is commonly heard in the derived forms "shot" or "shotto" making a phonetic allusion to the original phrase.
The first known reference to "riding shotgun" in print occurred in Western pulp fiction in the March 27, 1921 issue of the Washington Post's "Magazine of Fiction," in a story entitled "The Fighting Fool" by Dane Coolidge. It was used to refer to riding as an armed guard in the front of a stagecoach, next to the driver (this would usually have been on the left, as stage drivers traditionally sat on the right, near the brake). Historians have been unable to find a use of the term "riding shotgun" in the actual time of the Old West, when the terminology actually used was riding as "shotgun messenger." The use of the phrase in print to refer to automobiles occurred in 1954 simultaneously with the TV series Gunsmoke, which became extremely popular, and used the terminology of riding shotgun nearly weekly.
Today, many automobile passengers consider riding in the front passenger seat preferable to riding in rear seats largely due to it having greater control over leg room, an unobstructed view of the road in front, and access to the vehicle's audio and air conditioning systems. Another benefit is that entry and exit from the vehicle is often easier, especially in two-door cars. In addition, some passengers find that riding in the front seat better isolates them from the road, reducing car sickness. There is also a tradition in family life that adults (and/or the older child) sit in the front and children in the rear, a tradition reinforced in modern times by airbags installed in vehicle dashboards which are positioned so as not to allow smaller children to ride in the front seat; hence sitting shotgun provides a sense of adulthood.
Prior to the advent of seat belts and airbags, the front passenger seat was considered the most dangerous to be seated in if there were an accident; therefore the shotgun position also came to be known as the suicide seat.