From the competitors' point of view, a detailed and legible map is a reliable guide for choice of route, and it enables him to navigate along a route chosen as suiting his navigational skill and running ability. However, skill in route choice loses all meaning if the map is not a true picture of the ground - if it is inaccurate, out-of-date or of poor legibility.
Anything which bars progress is essential information - cliffs, water, dense thicket. The path and track network shows where the going and navigation is easiest. A detailed classification of the degrees of hindrance or good going helps the competitor to make the right decisions. Orienteering is first of all to navigate by map reading. An accurate map is therefore necessary for a good and effective route choice. No competitor should gain an advantage or suffer a disadvantage because of faults on the map.
The aim of the course planner is a course where the deciding factor in the results will be navigational skill. This can be achieved only if the map is sufficiently accurate, complete and reliable, and is also clear and legible under competition conditions. The better the map the course planner has, the greater the chance he has of setting good, fair courses, whether for the elite or for the novice.
Great detail on the map offers the planner many features for controls, and hence enables him to choose good legs, vary control sites and check that the controls are correctly placed on the map.
Controls are the most important building blocks of a course. Choice of sites, placing of the markers, checking their positions, and locating controls in competition, all put definite demands on the map. The map must give a complete, accurate and detailed picture of the terrain. For an international event, it must be up-to-date in all parts which could affect the end result of the competition. If it is not up-to-date it must be improved.
Courses should be overprinted at least for elite classes. For other classes they can be drawn by hand.