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.
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 HookPressing Buttons
As a general story-hook approach, think about the player-character -- his personal goals and his personal dislikes. If the hero is pursuing a specific goal, you have one of the minor villains, as a side-effect of the villain's master plan, thwart the hero's latest step towards that goal. Alternatively, if there's something the hero truly hates to see, have it happen -- and have the villains be responsible.
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.
ClimaxBloody Battle
This is the best Climax for an adventure involving the clash of mighty armies -- or for any adventure where, toward the end, the Master Villain and a large body of minions confront the heroes and their own troops. This finale is characterized by a monstrous clash between the two forces, with the heroes chewing through the enemy ranks to get at the Master Villain and his elite guards. It's strenuous, exciting, and classically simple.
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 IShacktown of the Oppressed
Part of the action centers around the tenements or shacks of the worst part of town; perhaps an allied NPC lives here or the characters are fugitives hiding out in the nasty part of town.
Specific Setting IICaves of Magical Folk
These can be either beautiful, glittering homes of gorgeous magical peoples, or the dank and terrifying lairs of horrible 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 IHard-Eyed Advisor
This is the sort of villain whom the heroes see in the Master Villain's throne room. He's hard-eyed and scary; life means nothing to him and he enjoys killing. He's also a good advisor to his master.
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/NeutralHero Worshipper
Some youth -- an urchin, a brother or sister of one of the heroes, or a child run away from home -- hooks up with the heroes, following them wherever they go, being admiring, talking to everyone (neutrals and villains included) about how wonderful and powerful the heroes are.
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 EncounterPress Gang
In any port city, the heroes, in a tavern or hostel, may find themselves set upon by ruffians employed by the city; these ruffians use clubs and strike to subdue. If the heroes fight and beat the ruffians, they find themselves wanted by the law for assaulting officers of the peace. And if they fight and lose, they wake up to find themselves sailors, headed far away from their quest! Now they must decide whether they're going to jump ship, mutiny, or just settle down toa few years of seafaring life.
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.
ChaseAerial
The heroes could be riding pegasi or friendly griffons or allied great eagles; the villains could be carried aloft by gargoyles or demons. The prospect of taking a mile-long fall if one's mount is hit is a very daunting and challenging one for the hero.
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 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 ConditionNo Hurting the Villain
For some reason, the heroes cannot afford to fight the villain directly. For instance, what if a demon possesses the body of the child of one of the characters, or a very important child spoken of in prophecy, one without whom the world will perish?
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 HerringLying Rumor
This is the worst and most useful type of red herring -- the interesting rumor which just happens to be false. In adventures of this sort, the best Lying Rumor concerns the Master Villain; it gives the heroes some "important" information about him which later turns out to be useless.
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.