DM Note: When the players discover the ravine area, read the following paragraph to them. Add whatever you feel is appropriate to the description of what they see, but be careful not to give anything away or mislead them. Information on how you should handle the whole area is given before the encounter area descriptions.]
START: The forest you have been passing through has been getting more dense, tangled, and gloomier than before. The thick, twisted tree trunks, unnaturally misshapen limbs, writhing roots, clutching and grasping thorns and briars all seem to warn and ward you off, but you have forced and hacked your way through regardless. Now the strange growth has suddenly ended - you have stepped out of the thicket into a ravine-like area. The walls rise rather steeply to either side to a height of about 100’ or so - dark, streaked rock mingled with earth. Clumps of trees grow here and there, both on the floor of the ravine and up the sloping walls of the canyon. The opening you stand in is about 200’ wide. The ravine runs at least 400’ west (actually 440’) to where the western end rises in a steep slope. Here and there, at varying heights on all sides of the ravine, you can see the black mouths of cave-like openings in the rock walls. The sunlight is dim, the air dank, there is an oppressive feeling here - as if something evil is watching and waiting to pounce upon you. There are bare, dead trees here and there, and upon one a vulture perches and gazes hungrily at you. A flock of ravens rise croaking from the ground, the beat of their wings and their cries magnified by the terrain to sound loud and horrible. Amongst the litter of rubble, boulders, and dead wood scattered about on the ravine floor, you can see bits of gleaming ivory and white - closer inspection reveals that these are bones and skulls of men, animals, and other things,. . . You know that you have certainly discovered the Caves Of Chaos.
NOTES FOR THE DM ON THE CAVES OF CHAOS CAVE AREA MAP: There are woods overlays and rough contour lines* shown on the map. These are only for surface movement references, and once your players are underground you should ignore these markings.
WOODS: The small groves and copses are thick growths, tangled and forbidding. You may, at your option, have characters encounter occasional monsters herein - stirges, humanoids (kobolds, orcs, etc.) from the caves nearby, or the like. Movement through these wooded areas is slow and difficult. Characters must move in single file. Even though not shown, there are single trees, shrubs, and bushes elsewhere.
UNDERGROUND: The caves, passages, and rooms of the complex are on different levels. Passages slope upwards and downwards between the contours, even where stairways are not shown. Areas are roofed by at least 5’ of solid rock. INTERIORS: Except where noted otherwise, all underground areas are natural or cut from living rock. All surfaces are rough (and easy for a thief to climb) with small ledges, minor cracks, small holes, etc.
RANSOMING PRISONERS: Organized tribes can optionally be allowed to take player characters prisoner, freeing one to return to the KEEP in order to bring a ransom back to free the captives. Set the sums low - 10 to 100 gold pieces (or a magic item which the ransoming monsters would find useful) per prisoner. If the ransom is paid, allow the characters to go free. Then, without telling the players, assume that this success brought fame to the capturing monsters, so their numbers will be increased by 2-12 additional members, and the tribe will also be very careful to watch for a return of the adventurers seeking revenge for their humiliating captivity. The period of extra alertness will last for 1-4 weeks; the increase in numbers is permanent.
TRIBAL ALLIANCES AND WARFARE: You might allow player characters to somehow become aware that there is a constant fighting going on between the goblins and hobgoblins on one side and the orcs, sometimes with gnoll allies, on the other - with the kobolds hoping to be forgotten by all, and the bugbears picking off any stragglers who happen by. With this knowledge, they might be able to set tribes to fighting one another, and then the adventurers can take advantage of the weakened state of the feuding humanoids. Be careful to handle this whole thing properly; it is a device you may use to aid players who are few in number but with a high level of playing skill. It will make it too easy if there are many players, or if players do not actually use wits instead of force when the opportunity presents itself.
MONSTERS LEARNING FROM EXPERIENCE: Allow intelligent monsters (even those with only low intelligence) to learn from experience. If player characters use flaming oil against them, allow the monsters to use oil as soon as they can find some. If adventurers are always sneaking up on them, have the monsters set warning devices to alert them of intruders. If characters run from overwhelming numbers, have the monsters set up a ruse by causing a few to shout and make noise as if there were many coming, thus hopefully frightening off the intruders. This method of handling monsters is basic to becoming a good DM. Apply the principle wherever and whenever you have reason.
EMPTIED AREAS: When monsters are cleared out of an area, the place will be deserted for 1-4 weeks. If no further intrusion is made into the area, however, the surviving former inhabitants will return or else some other monster will move in. For instance, a thou1 might move into the minotaur’s cave complex (I.), bringing with him whatever treasure he has.