Random Adventure Generator

ThemeComedy
This adventure is fun for fun's sake. Its basic purpose is to provide humorous entertainment with a minimum of actual danger or tragedy.
GoalProtect Endangered NPC(s)
One or more NPCs are in danger, and the characters must protect them. They might be doing this for a reward, or because one or more of the NPCs is a friend or relative of the character. You need to decide what the characters are protecting the NPCs from. The NPC might be a wealthy or powerful person being sought by assassins or kidnappers. The NPC might be a whole village of peasants who are being terrorized by a bandit chieftan.
Story HookNot in Kansas
The PCs are minding their own business and find themselves transported to a strange place. They must figure out where they are, why they are there, and how to escape.
PlotGeographic Progression
This is the simplest sort of adventure plot. The heroes have an area to investigate or travel through; they have encounters based on where they are. For instance, the traditional dungeon, where monsters are tied to specific rooms or areas. Or, if the heroes are travelling along a narrow valley or through an enchanted forest, they might suffer ambushes and other encounters fixed to various points along their travel plan. The plot, then, is getting to the villain by surviving the intervening obstacle encounters.
ClimaxScattered Duels
In this climax, the heroes have gotten to the end of their quest -- they may have broken into, sneaked into, or escaped from imprisonment within the villain's citadel, or have marched into the little town where the villain is holed up -- and they become separated. You can separate them by having traps and tricks break the party apart, by having them see two or three things they must resolve (such as danger to innocents or the appearance of minion villains) pop up simultaneously; they'll have to run in all directions at the same time or suffer failure. Once the party is broken down into bite-sized chunks, you confront each individual or small group with the enemy or enemies he most deserves to face -- his personal enemy, the monster which defeated him before, etc. -- for a grand series of climactic duels.
General SettingOn the Sea
Most of the action occurs on the sea -- the heroes are shipborne for some reason, docking in lots of ports. Again, this is good for adventures where the heroes are investigating clues left all over the map, are part of some trading enterprise, or are being pursued by villains.
Specific Setting IRuins
These can be the ruins of some ancient civilization, an abandoned temple or castle, incomprehensible blocks of stone arranged by ancient gods, etc. They can be magical or normal, inhabited by normal animals or by monsters, centers of magic or just tumbled-down buildings.
Specific Setting IILost City
This is the remnant of some lost civilization or expedition, still thriving in some forgotten corner of the world. Remnants of lost civilizations can even inhabit cavern systems beneath campaign cities, preying on the above-worlders for their goods, slaves, and sacrifices.
Master VillainDestroyer
This villain is like the Corruptor, except that he likes destroying instead of corrupting. He operates like the Conqueror, moving in his armies -- often nonhuman or monstrous armies -- and destroying everything in sight. Again, the Destroyer could easily be an evil god or demon, meaning the heroes wil have to find his weakness in order to thwart his current plan.
Minor Villain IInquisitor
This villain is the one who interrogates the heroes and NPCs captured by the villains. He accompanies the other Minor Villain out into the field and works on anyone captured; he enjoys inflicting pain and suffering.
Minor Villain IISingle-Minded Soldier
This most trustworthy of villain minions is the experienced, competent, persistent soldier -- a field-trained officer who serves the villain with military precision. He is usually encountered in the field as leader of the villain's field operations. He is not encountered directly until the middle of or the latter part of the adventure; until then, the heroes encounter only his subordinates.
Ally/NeutralRomantic Loony
Somewhere, the heroes bump into a lunatic who falls immediately in love with a player-character and won't leave him or her alone. This character may be a love-smitten village lass or nebbishy adventurer. Whatever the origin, this character must be hopelessly in love with the character but have some trait which keeps the character from reciprocating; perhaps the loony is too plain, too crazed, or too stupid. Whatever, he or she really is sincere in his affection for the character.
Monster EncounterNocturnal Predator
This is a classic monster encounter; the arrival of a hungry carnivore in the middle of the night. Usually, this attack happens to heroes camping between villages or out in the deep wilderness; a wild animal, attracted by food odors (from the heroes' campfire or from the heroes themselves) sneaks in for a bite.
Character EncounterBureaucrat
Some time in their adventure, the heroes must deal with the local government and run into that most horrible of nuisance monsters, the bureaucrat and his red-tape dispenser. The heroes don't have the right forms. When they have the right forms, they forgot to fill them out in triplicate. And so on.
DeathtrapRock and a Hard Place
This trap starts out as an Animal Pit, Pit and the Pendulum, or Tomb Deathtrap, but an obvious escape suggests itself very early on. Trouble is, it leads into even worse danger. The hole out of the animal pit may lead to the lair of an even worse animal; it may lead through a succession of dangers (collapsing old catacombs, into an underground river, into a den of zombies) before the heroes reach the light.
ChaseHorseback
This is a relatively short chase -- it only needs to go on for a mile or so before even the best horses are winded. If it goes on longer than that, the horses may collapse and perhaps die.
Omen/ProphesyComet's Progress
Events during the adventure may be enlivened by a large and menacing comet which appears in the night sky for several days during the scenario; the locals take it for an omen of doom. The comet may be the result of magic being used by the Master Villain, or the comet's appearance can pertain to an old legend involving the Master Villain.
Secret WeaknessLack of Familiarity
The Master Villain, if he comes from the past or another dimension, or belongs to an alien race, might be sufficiently unfamiliar with this world that he essentially defeats himself. How? By making incorrect guesses about human behaviour. One classic error involves underestimating the human capacity for self-sacrifice.
Special ConditionTime Limit
Finally, the most obvious condition to place on an adventure is to give it a time limit. If the Master Villain is going to conclude his evil spell in only three days, and his citadel is three hard days' riding away, then the heroes are going to be on the go all throughout the adventure -- with little time to rest, plan, gather allies, or anything except get to where they're going.
Moral QuandryAlly Quandry
You set up the situation so that the heroes have a good chance at defeating the Master Villain if they get the aid of two specific individuals, probably experts in fields relating to the villains' activities. But the two experts hate one another and refuse to work together, even if it costs them their world.
Red HerringFalse Path to the Artifact
Once again, if the heroes have had too easy a time finding the artifact capable of destroying the villain, give them trouble this way: When they get to the place where the artifact is supposed to be contained, they find the coffer or chamber or whatever empty, obviously looted by robbers, who have scrawled such remarks as "Kelrog was here!" upon the walls.
Cruel TrickWanted by the Law
One final complication, one which occurs pretty frequently, is when the heroes are wanted by the law. When they're wanted by the law, they have to travel in secret and very limited in the resources they can acquire.

Based upon tables from the Dungeon Master's Design Kit by TSR, Inc.