One-Design is a racing method which may be adopted in sports which use complex equipment, whereby all vehicles, gliders or boats have identical or very similar designs or models. In motor racing, it is also known as Spec series, and one-make racing.
As manufacturing technologies became more efficient and effective over the course of the 20th century, racers in a number of sports realized that there was an important need to equalize the design of the equipment that they were competing in. One-Design racing is the ultimate result of this. Most often, the members of a One-Design class are near identical as a direct consequence of all deriving from the same production line. Sometimes they are checked or measured at stages in their use to guarantee continuing conformity to the standard design. The important factors being measured in One-Design racing help to equalize the vehicles and put more emphasis on the skill of the competitors.
One-Design is utilized in a variety of racing sports.