SPELUNKER is a simulation program, not a treasure hunt or a dungeons-and-dragons type adventure game. The program uses your computer's random number generator to create a cave complex, with passageways, rooms, domes, and pits. Your task is to explore and map this cave complex. To assist you in this task you may, at your option, carry along a knapack loaded with your choice of items you think you may need, such as spare batteries, ropes and grapples, and a map showing any previous explorations that have been done in this particular set of caves (the map may, in an emergency, be updated inside the cave). Care is required, particularly around pits, it is possible for a careless person to slip and fall in, ending that particular caving trip quickly but painfully.

Caves are developed on up to five levels. Each level is contained within an 11?11 square matrix, allowing up to 121 rooms and passageways per level. Levels are connected by pits and domes. Each cave the program generates is unique?there are millions and millions of possible room arrangements! Though the caves may seem small in external dimensions, you are not likely to run out of surprises within them.

The caves are all what cavers call walking passage?there are no crawlways, squeezeways, or fat man's miseries (serious cavers may regret this). There are also virtually no speleothems (the programmer regrets this, and will be addressing it in the next version of the program). Though the rooms and passageways vary significantly in shape and size, they are similar enough to each other to cause confusion if you do not pay attention to where you are and in what direction you are facing?just as in a real cave.