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.
GoalClear Name
The name of one of the characters or an NPC has been sullied and the characters must clear it. The characters must find out a) why the name has been smeared, b) who is responsible, and c) why the responsible party is doing it; then they must find evidence to convince everyone they're telling the truth.
Story HookGrim Necessity
If the hero doesn't involve himself with this adventure, he's going to find himself suffering or dead -- period. That's the hook to bring him into the adventure... but you have to determine why he'll suffer or die if he doesn't become involved.
PlotAccumulation of Elements
In this sort of plot, the heroes have to go from place to place -- perhaps covering very little area like a city, perhaps roaming the known world -- and accumulate elements to be used against the Master Villain. These elements may be clues, pieces of an artifact, evidence, or allies.
ClimaxThrone Room Duel
This is set up much like the Scattered Duels, except that you don't separate the heroes. It's harder to control whom fights who in this situation... but if it doesn't matter who has the final duel with the Master Villain, this is a classic climax choice.
General SettingCosmopolitan City
Most of the story takes place in a large, sophisticated city; center the villain's plot and activities around that city. This setting is best suited to adventures involving more people than monsters; most of your villains should be human or demi-human.
Specific Setting IMansion of a Lord
This can be the home of a villain -- the characters may have to break in and rescue someone or steal evidence, or break out if they've been captured -- or of a heroic ally, in which case it may be used as the headquarters for the heroes' plans and activities.
Specific Setting IILegendary Forest
This classic adventure site is the sometimes dark and fearsom, sometimes light and cheerful, always magical and incomprehensible forest inhabited by the oldest elven trives and most terrifying monsters.
Master VillainRavager
This Master Villain is like the Destroyer, except that he terrorizes a very limited area -- such as a village, island, castle, or clan stronghold. (He may want to destroy the whole world but be trapped where he is; perhaps his efforts to free himself constitute the adventure's plot.) He stays in his area and terrorizes whatever comes into it.
Minor Villain ISingle-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.
Minor Villain IICorrupted Hero
This villain was once a hero, possibly one known to the players. He was seduced by the dark side of the dungeon master. Because of his own weakness, or of a curse, he has become a villain, a pawn of the Master Villain.
Ally/NeutralCongenial Madman
This fellow is a pleasant, happy lunatic whom the heroes encounter; after the initial encounter, he follows them wherever they go, commenting on their plans, behaving strangely, getting underfoot, and -- very occassionally -- proving to be a real help.
Monster EncounterTerrain Monster
Don't forget the simple run-in with the animal belonging to the terrain where the heroes are: Every type of wilderness has its predators and big, nasty herbivores.
Character EncounterOld Friend at the Wrong Time
When the heroes are trying to sneak through a guardpost, citadel, or city where they can't afford to be recognized, one of the characters' old friends recognizes him and loudly renews their acquaintance in full view of the guards looking for the characters. This usually leads to an exciting chase as the heroes must escape.
DeathtrapMutually Assured Destruction
In this very nasty deathtrap, the heroes are bound up in such a manner that any one of them may get free of his bonds -- but when he does, all his friends perish. Obviously, the heroes' task is to find some way for everyone to get out alive. Perhaps an intricate series of cooperative rope-cutting will defuse the trap; perhaps a coordinated maneuver will get everyone free as the trap is being sprung.
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 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 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 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 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.