Random Adventure Generator

ThemeEspionage
Espionage adventures are active, grim scenarios involving spying and perhaps other cloak-and-dagger deeds such as assassination or rescue.
GoalRescue NPC(s)
The characters must rescue one or more kidnapped NPCs, probably from the stronghold of the kidnapper. Obviously, they must get to said stronghold, break in, rescue the kidnappee, break out, and escape back to safety; this usually requires careful and clever planning and a large dose of luck.
Story HookHero Offended
Someone greatly offends the hero, so much so that he'll pursue his offender right into the adventure. (Note that this usually means that the offender is a minion of the Master Villain. You'll have to decide whether the minion offended the hero precisely to bring him into the adventure or just as a side-effect of his ordinary villain activities.)
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.
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 ITavern/Inn
This is a classic fantasy setting, the residence of travelling heroes and the home of the tavern brawl.
Specific Setting IIDemi-human Community
In wilderness areas, this will be a large community of demi-humans -- elves, dwarves, halflings, whatever -- or intelligent nonhumans such as orcs. If your action is taking place in a city, this could be a hidden community (such as a secret underground dwarf community) or a section of the city inhabited mostly by demi-humans.
Master VillainOrganizer
This Master Villain is the head of the local criminal syndicate -- the Thieve's Guild or slaver ring, for instance. He's cold-hearted and unsympathetic, and human life means nothing to him. He employs assassins and musclemen against the heroes, and can only be reasoned with when it's going to profit him more to cooperate with the heroes than kill them.
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 IIChief Assassin
The Chief Assassin is the favorite killer of the Master Villain. The Assassin works mostly in the field, first killing witnesses who might prove harmful to his master, then zeroing in on the player-characters. He usually meets his end before the adventure's climax, but he may taken one of the heroes down with him.
Ally/NeutralTragic Fellow Hero
The heroes are in the company of some hero well-known to them; he may have been a companion or ally, or they may just know him by reputation. He is a tragic figure; he may have lost his family to the master villain, or lost his properties and titles, or be afflicted with a curse he cannot be rid of, or be committed to a quest he knows will take his life. He's dour, and gloomy, prophesying doom and having no fun at all.
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 EncounterBelligerent Soldier
The billigerent one has just had his ears pinned back by his commanding officer and is anxious to take it out on some hapless civilian. If this is a city gate, he claims that the hero's papers are wrong or that he recognizes the hero from descriptions of a wanted criminal; if this is the streets, he insults the hero's lack of military bearing, pretty looks, clothes, smell, companion, or whatever it takes to provoke a reaction.
DeathtrapAvalanche
This is an outdoors trap. Some time when the heroes are in a narrow canyon or gorge, or are on a snow-covered mountain, their enemies can arrange to dump an avalanche upon them (rocks and boulders in the first instance, snow in the second).
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/ProphesyReincarnation
The hero, seeing the portrait of some long-dead nobleman, may be surprised to see his own face staring back at him. All evidence points to the fact that our hero is the reincarnation of this person, and the Master Villain may desire to destroy any trace of that nobleman's existence. Just as appropriately, this long-dead nobleman may have died after making some important choice -- such as choosing love over career or career over friends; and the choice he faced is identical to the one the hero now faces. Will our hero defy the prophecy and choose as he did in a previous life, or will he choose the other option and see what happens?
Secret WeaknessHoly Symbol
The villain may have the traditional weakness to a specific holy symbol -- but don't choose just an ordinary one. It may be a holly symbol no longer used by the church, or may be some forgotten variation of the current symbol. (For instance, the cross may not work, but a variation -- such as the Roman cross -- might; alternatively, it might have to be a holy symbol which has undergone some unfamiliar ritual.)
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 QuandryHonor Quandry
You want to use this on the character with the most strongly developed sense of personal honor -- someone who has lived all his life by a strict code. Toward the end of the adventure, this character realizes that the best way to defeat the Master Villain is a violation of that code. For instance, the character might be a paladin, who discovers that the only possible way for the heroes to defeat the Master Villain is to sneak up on him and stab him in the back.
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 TrickHeroes Must Work with Villain
If they have to work for the villain, it's due to some hold he has over them -- probably, he's kidnapped one of their NPCs and will kill this person if his demands aren't met. Put the heroes through the encounter where they have to do something they are loathe to do, such as sack and pillage a temple, before they have the opportunity to retrieve their friend.

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