Random Adventure Generator

ThemeAction/Adventure
This is the most common and straightforward sort of adventure there is. In the Action/Adventure scenario, you present your characters with a task and then confront them with obstacles to overcome in order to accomplish the task successfully.
GoalThwart Monstrous Plan
This is a classic fantasy-adventure plot: The characters learn of some horrible plan made by a monstrous enemy, and must thwart it before the kingdom is lost or the world is destroyed. This is an epic goal, and usually requires that the characters go to all sorts of places, rounding up allies and artifacts, before being strong enough to face their enemy.
Story HookMystery Woman
Create an NPC "mystery woman" sure to be fascinating to your hero and have her keep appearing inexplicably in his life. As he becomes interested and investigates her, he keeps stumbling across the villain's plans and becomes inextricably mired in the plot. (For female player-characters, the Mystery Man is just as useful.)
PlotSeries of Villains
This is a very dramatic plot, and very well-suited to oriental campaigns. In it, the heroes have undertaken a quest, usually the finding and defeat of the Master Villain. They may have to travel to his citadel, or head off in another direction to find some artifact capable of defeating him, or run away from pursuing villains until they can figure out what's going on. All along their route, they are set upon by villains -- each villain has a name and distinct personality, and each encounter is life-or-death for the heroes and villains; the villain never escapes to safety if the tide turns against him, he fights unto death.
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 SettingOn the Road
Most of the adventure takes place on the road, as the heroes are travelling from place to place. This is especially good for adventures where heroes are investigating a wide-ranging mystery, are part of a caravan, or are being pursued by loathesome villains.
Specific Setting ITemple/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.
Specific Setting IIClassic Dungeon
This would be the standard monster-filled labyrinth; perhaps it's a nesting ground for the master villain's monster troops.
Master VillainAdvance Agent
This villain is the vanguard of some sort of invastion; often, he is trying to open up a portal to a dimension full of trapped demons and evil gods.
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 IILovable Rogue
This character is like the Master Villain of the same name, except that he has no minions of his own and serves at someone else's bidding. However, he's very independent, not always working in his employer's best interests; he often makes fun of the Master Villain's pretensions and may suffer that villain's retaliation because of it.
Ally/NeutralAbsent-Minded Expert
The characters find they need an expert in some fields -- pottery, alchemy, whatever -- but all they can find is a somewhat daffy and absent-minded master of that subject. He's useful when around his subject matter, but otherwise absent-minded, incautions, in frequent need of rescuing, etc.
Monster EncounterPowerful Tester
Here, some powerful, intelligent monster with shapechanging ability turns into a human form. When the heroes encounter him, he is in need of help or having trouble. He also obviously can't reward the heroes for their help, and will only serve to slow the heroes down from their quest. If the heroes help him anyway, the Powerful Tester reveals himself in his true form and offers to aid the heroes in their quest.
Character EncounterMean Drunk
The Mean Drunk works much like the Belligerent Soldier except that he's not as tough, is of course drunk, and is usually accompanied by other Mean Drunks.
DeathtrapFramed
One or more of the heroes is accused and convicted of a capital crime -- one for which the mandatory punishment is death. The heroes must escape or die, and they're escaping from the well-built, well-protected prison of the local authorities.
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/ProphesyHero Fulfills Prophecy
This is the most useful sort of prophecy. In the early part of the adventure, one of the heroes discovers that he fulfills some ancient prophecy.
Secret WeaknessSecret Embarrassment
Finally, the villain may have some aberration or secret shame that will force him to flee when he is confronted with it. It could be something as simple as the fact that his nose is too big, or that he is a small and nebbishly wizard pretending to be some vast, powerful demonic power. When his shame is revealed, he is too humiliated to continue; this is a good option for comedy adventures.
Special ConditionCoping with a Curse
The curse might be making the hero progressively uglier, might be draining out his life-force (he's losing experience which will be retruned if he succeeds), or might be making him progressively insane. Each day, as he sees his reflection in a mirror or pond or fountain, he'll know himself to be less than he used to be.
Moral QuandrySaving Quandry
Finally, another classic quandry puts the heroes in the position of choosing between a grand opportunity to hurt the Master Villain -- or saving the lives of a number of individuals.
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.