Random Adventure Generator

ThemeHorror
This type of adventure is designed to scare both the characters and the players. Just having a monster attack is not enough for a horror theme; the monster must first frighten the characters.
GoalEscape
Early in the adventure, the heroes are captured. The remainder of the adventure consists of them learning enough so that they can escape. They have to get to know their fellow prisoners, learn the prison's routine, inventory their possessions, acquire other possessions they need, plan an escape, and execute it.
Story HookOld Enemy
This is a straightforward story hook; the hero learns that his oldest enemy is back and is very active in the campaign, up to something. The hero will naturally want to investigate and will walk right into the story.
PlotEvent
For this plot, choose some sort of event -- a tournament, a holiday, a celebration called by the king, a masked ball, or whatever -- and set the commencement of the Master Villain's plan against that backdrop.
ClimaxPrevented Deed
Here, the heroes have been defeated -- captured by the Master Villain, or so thoroughly cut up by his minions that all believe them to be dead. And the heroes have learned, from the bragging of the villain, loose talk of his minions, or examination of clues, what is the crucial event of his master plan. In any case, the battered and bruised heroes must race to this site and have their final confrontation with the villain, bursting in on him and his minions just as the knife or final word or key is poised, and prevent the awful deed from taking place -- and, incidentally, defeat the master villain and minions who beat them previously.
General SettingExotic Distant Land
The adventure will take the heroes to some fascinating and exotic distant country, where they'll have to cope with new customs, monsters unfamiliar to them, and very colorful NPC encounters; choose one of the more fascinating foreign lands from your campaign world.
Specific Setting IClassic Dungeon
This would be the standard monster-filled labyrinth; perhaps it's a nesting ground for the master villain's monster troops.
Specific Setting IITemple/Church
This can be either the church of some lofty and good diety, or the dark and grisly temple of some horrid deity (doubtless filled with evil soldiers and monsters), or even the temple that the madman villain has dedicated to himself for when he becomes a god.
Master VillainAvenger
This villain seeks to avenge some wrong he thinks he's suffered. He may be right; he may have suffered a wrong, and this makes him a little more sympathetic than villains who are purely evil. The Avenger uses his organization -- thugs and bribed officials -- to get at the one who wronged him, and will want either to duel (singly) the one who wronged him, or to put the wrongdoer in a deathtrap.
Minor Villain ISnivelling Vizier
The Vizier is a throne-room villain. Functionally, he's rather like the Hard-Eyed Advisor, offering tactics and advice to his master; but he's an ooily, sleazy, cowardly sycophant. He's usually brilliant in his field of advice but has no combat abilities.
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/NeutralGrumpy Old Professional
Again, the heroes need an expert in a certain field -- this time a craft or art, such as blacksmithing, engineering, horse-training, or whatever. The only or best professional they can find is an aged expert. He's grumpy, cranky, and sharp-tongued; he constantly complains about the food, the weather, his companions, the decline in skill of his co-workers since he was a young man, the road conditions, the rotten pay he's receiving, and so on.
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 EncounterThief
At some point in their adventure, the heroes have a run-in with thieves.
DeathtrapStampede
Should the heroes ever cross plains or prairies, their villainous enemies may wish to stampede a herd of large animals at them. Alternatively, beasts in the forest may be stampeded by fires set by the villains; in this case, it will not be one sort of animal charging through, but a mixture of terrified forest animals, from the smallest fox-cub to the largest bear.
ChaseFootrace
The chase involves the characters on foot, probably through such terrain as city streets or the corridors of a palace. One hero may realize that the's being pursued by a party of enemies and choose to run for it; the heroes may have caught up to the Master Villain, prompting him to run for his life.
Omen/ProphesyInnocent Fulfills Prophecy
An innocent could fulfill a prophecy -- one which endangers his/her life. This innocent might, for instance, be the one who is supposed to slay the king, but is not a mighty adventurer able to protect himself from the king; the heroes may find themselves sheltering and helping this poor dupe.
Secret WeaknessLove
The Master Villain possesses the "weakness" of genuine affection or love -- probably for some NPC, though it could be very intriguing if the object of his affections is a player-character. The heroes can then defeat the villain by holding his loved one hostage, or proving that his loved one will be seriously harmed, betrayed, or killed if the villain keeps up with his activity.
Special ConditionNo Weapons Allowed
At some point in the story, the heroes must surrender their weapons. Perhaps they're visiting some quarter of the city where weapons are not allowed; or a particularly peace-loving temple. In any case, once they're there, they are attacked by enemies belonging to the Master Villain.
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 HerringLoony who Has It Wrong
You can have the heroes "aided" by a so-called expert who is actually a lunatic who doesn't know anything about what he's talking about. Once he's led the heroes off to some remote part of the continent, his evasive answers and bizarre behaviour will alert them that he really doesn't know anything about what he's pretended to be an expert on.
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.