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.
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 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.)
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.
ClimaxScattered Duels
In this climax, the heroes have gotten to the end of their quest -- they may have broken into, sneaked into, or escaped from imprisonment within the villain's citadel, or have marched into the little town where the villain is holed up -- and they become separated. You can separate them by having traps and tricks break the party apart, by having them see two or three things they must resolve (such as danger to innocents or the appearance of minion villains) pop up simultaneously; they'll have to run in all directions at the same time or suffer failure. Once the party is broken down into bite-sized chunks, you confront each individual or small group with the enemy or enemies he most deserves to face -- his personal enemy, the monster which defeated him before, etc. -- for a grand series of climactic duels.
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 IDemi-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.
Specific Setting IICatacombs
These can be catacombs beneath a living city or a ruined one; they can be long-forgotten or still in use.
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 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 IICoward
This character is an ordinary grunt minion of the Master Villain, but he's a coward. He's deathly afraid of the Villain and the heroes. He's best used when you plan to have the heroes captured; by his mannerisms, you can make it clear to them that this fellow is a coward and they will begin to work on him psychologically.
Ally/NeutralTalkative Barkeep
This classic encounter is the garrulous innkeeper who has information the characters want; trouble is, they'll have to bribe him to get it, or agree to stay at his inn, or buy a lavish meal, or listen to his incessant stories about his career in the army, or whatever.
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 EncounterSeducer
One of the characters is invited to a romantic liaison with an attractive local. This local can just be interested in a brief tryst, could fall madly in love with the hero and follow the hero through the rest of the adventure, could be a Loving Deceiver monster encounter, could be a thief and rob the hero blind, or could be a spy or assassin working for the Master Villain.
DeathtrapTomb Deathtraps
Another classic type of trap is the sort of triggered trap left behind in abandoned tombs, ruins, and catacombs. Here, a hero who touches the wrong step, floor tile, wall brick, torch bracket, mounted gemstone, or other device will trigger some sort of ancient trap designed to kill tomb-robbers and intruders.
ChaseSpecial Terrain
You can make any chase more memorable by having it take place in a setting to which it is utterly unsuited. For instance, horse chases are fine and dramatic when they take place through the forest, out in the open plains, or along a road -- but they become diabolical when they take place inside the Royal Palace or in dangerous, labrynthine, treacherous catacombs.
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 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 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 QuandryRespect Quandry
This is much like the Ally Quandry, only at a greater distance. The heroes have been utilizing the aid of two (or more) powerful NPC allies. Now, in the course of the adventure, the heroes come across a task which can be accomplished in one of two ways -- say, through military intervention or by esoteric magic. The problem is, the NPC allies are arguing for different choices, and the one whom the heores choose against will no longer aid them.
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 TrickVillain is Related to Hero
In this very irritating complication, one of the heroes discovers that the Master Villain is related to him. The villain might be his long-lost father or twin; perhaps this relative is not long-lost after all, but has secretly been a Master Villain for years, and only now has the hero discovered it.

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