Measure a bearing and a distance off the map, choose your way around the hills, and reach the checkpoint on as little stamina as you can.
The map shows a start triangle and a checkpoint circle. Each leg you type is a compass bearing (0° is north, 90° east, 180° south, 270° west) and a distance in metres; you walk that line, and you finish when a leg ends inside the circle. Measure both off the map: grid squares are 100 m, there is a scale bar, and a compass ring is drawn around where you stand.
Every leg costs stamina: 1 point for every 10 m walked, plus far more for every metre climbed (walking downhill costs only the distance). So the straight line is not always the cheapest: going around a hill can beat going over it. Brown contour lines join points of the same height, every fifth one is thicker, and the highest and lowest points are marked with their heights.
On Normal the contours are 20 m apart. Walking 100 m on the flat costs 10 stamina, but climbing one contour, 20 m, costs as much as walking about 167 m. A hill five contours high between you and the checkpoint therefore costs over 80 extra stamina to climb, while walking around it might add only 200 m, or 20 stamina.
Say the cheapest route needs 55 stamina in 3 legs, so par is 4. Reach the circle in 4 legs having used 70 stamina and you are 79% efficient: 1,000 + 786 = 1,786. Take a fifth leg instead and you score 1,686. When the course ends, the cheapest route is drawn as a dashed line so you can compare.
Compass Course practises the core skills of map-and-compass navigation: measuring a bearing and a distance off a map, reading height and steepness from contour lines, and weighing a shorter route against an easier one.
Orienteering grew out of military land-navigation training. The Swedish word orientering was first used in 1886 at the Karlberg Military Academy for crossing unfamiliar terrain with a map and compass, and the first civilian competition open to the public was held in Norway in 1897 (orienteering: history). In the sport, the fastest route between two controls is not always the shortest one, which is why route choice matters (orienteering: basics).
The map borrows orienteering's conventions: the course is overprinted in purple or red, the start is a triangle, and magnetic north lines are printed in blue (orienteering map). On any contour map, the contour interval is the height difference between neighbouring lines, and close contours mean a steep slope (contour line).
The stamina cost follows Naismith's rule, devised by the Scottish mountaineer William W. Naismith in 1892: allow one hour for every 5 km forward plus an extra hour for every 600 m of ascent (Naismith's rule). The basic rule says nothing about descent, so in the game going downhill costs only the distance.
Compass Course is an original PlayPendium game. Every course is generated from a seed, so the Daily is the same for everyone, and the cheapest route it compares you with comes from a search of the whole map on a 25 m grid, so it is a fair target to measure yourself against. It runs in the browser with no install or account.