Minigolf Open Standard courses are those built with a surface of artificial grass and are most common in North America and Great Britain. Minigolf Open Standard (MOS) courses are also commonly known as Adventure Golf and Crazy Golf.

This type of tournament course was offcially approved by the WMF in 2007, in order to strengthen the position of the WMF and to spread the minigolf movement all around the world. This new section allows all member nations of the WMF to develop under general basic conditions and rule their “own” MOS courses with individual (non-standardised) lanes. This open strategy of the WMF allows each member nation to approve existing courses for national tournaments and international sport events by its own decision in the name of the WMF.

The size and shape of the lanes are quite different from miniaturegolf, feltgolf and concrete courses. As MOS courses contain many different hazards to the other three approved course type, specific rules are either published in a course rule book, which is available at the course for all players, or explained to all players before tournament play begins.

New types of courses with different materials used for the surface, frames and obstacles, and different sizes of the lanes are covered by the category of MOS. New MOS courses are being built in a lot of the newly WMF registered national associations and are going to be produced for national promotion of minigolf in these countries.

Even when these courses look like small editions of golf holes, minigolf, including MOS, is a separate worldwide sport acknowledged by Sport Accord and by the International Golf Federation.

As there are a number of existing well designed courses throughout the world there is the potential that approved MOS courses will help minigolf sport grow in popularity and further establish itself as a sport in an increasing number of countries worldwide.