I generally use Qags as my default system of choice, but just about any system can be used here.
some of these are ideas i threw out from my "Bag" (you'll come to know the bag if you don't already), some are things that i have run, some references from books, some references from pdfs available now online.
there are numerous ways to get results from this chart, 2d20s, percentile die, random number draw. however you want to do it is fine.
Characters (with a capital letter) refer to PCs, the rest you can figure out.
without further ado:
101 Random Adventure Hooks
1: The Characters are sent into space to work at a refinery on a trash landfill planet, which is soon attacked by a race of flying pig-like aliens.
2: The Characters are toys that are either broken or missing parts, and that which they need is being held for ransom by the new toy(s) in the room.
3: The Characters are in medieval times where magic is real and mythical creatures exist. The group has to stop a rampant problem with pod people who are killing and replacing the villagers.
4: The Characters are part of a gang war where every gang involved has a distinct and flamboyant theme. They are about ready to rumble when a new gang called “The Risen” arrives on the scene and attempts to bring about the end of the world. The hooded leader of The Risen sounds a lot like Bruce Campbell.
5: The Characters are a clan of ninjas who are being sent on a mission of certain death. There will be an enormous body count by the end of this adventure. Dead bodies everywhere.
6: The Characters are part of a special force of different military branches, the best of the best. They are trying to stop a mad scientist who has gained an item of power which grants him control of a giant monster.
7: The Characters go to a high school party in an abandoned insane asylum. The fun stops when they find that one of the party-goers has been eaten, and all the exits are locked.
8: The Characters are citizens of a sleepy suburban town that is slowly being overrun by a type of killer fungus that is both intelligent and mobile, and is turning the population into mushroom men. Tentacles are optional.
9: The Characters are High School Students, and the local outcast has found an old crown that grants him unimaginable powers. The outcast is systematically changing everything about reality, and has brought in undead as his personal muscle. Can the group stop him before all reality is broken?
10: The Characters wake up in a pit, with a severe case of amnesia. There are empty bottles of booze everywhere, and they hear chanting coming from somewhere nearby the chamber. Can the characters escape before they become a sacrifice to some unknown entity?
11: The Characters are on a slowly sinking cruise ship. The reasons are unknown as to why the ship is sinking. Additionally, there is something on board with them that is making escape significantly more difficult.
12: The Characters have all switched bodies with another member of their group. They need to find the cause to why this has happened.
13:There is a disgruntled troll running amok in the local quick stop corner market. Can the Characters stop the menace and still get some beer before closing time?
14: The lost notebook of da Vinci is found in a heap of old books in an old book store. It ends up in the possession of one of the Characters. Strange people are now staking the Characters. Can the group figure out why secrets of the notebook before the stalkers get too close?
15: The Characters are superheroes. When the main villain of their beloved city finally kicks the bucket, every two-bit villain now vies for his spot. Can the Characters survive the crime onslaught?
16: The Characters are looking for a bundle that an old hermit hid somewhere in an abandoned hospital. Rumor has is that the old man knew where a great treasure was hidden. The problem is that the ghost of the old man is very protective of his secret.
17: The Characters are crew member on the Doppler Effect, a space station on the far reaches of the galaxy. They are the first line of defense against an oncoming armada of alien ships.
18: The Characters are living in a small desert town in the middle of nowhere. The whole town ins being reunited by dead loved ones. Is this because of a scroll that one of the Characters found, or is this occurring because of a nearby nuclear facility going critical and spilling out noxious chemicals?
19: The Characters are outcasts in a nuclear wasteland. They are running low on provisions, and the only way they are going to get what they need is by doing some odd jobs for one of the big settlements' boss. They are sent to clear out a colony of mutants deep in the recesses of an old gorge.
20:The Characters are part of a long running Japanese cartoon show that children love all around the world. The show is edited badly, with constant redos, flubbed lines, and bad dubbing. Whether this show is reality or not is up for the characters to decide.
21:The Toxic Gerbil is attacking a nuclear power plant. It is up to our heroic Characters to try and stop the radioactive rodent before he takes out the entire city.
22: The Characters are spies, and they have uncovered a dastardly plot. A shadow company is selling “Beer of Brilliance” to the masses, but it is a poisonous liquid that has similar effects to brainwashing. Can our intrepid heroes save the day and our beer?
23: Settlers traveling out west for a better life encounter a dangerous evil presence. Luckily for the Settlers, the Characters are with them, and they are members of a secret monster hunting society. Can they overcome this unknown evil?
24: One of the Characters is left a family heirloom from a dying distant uncle. The heirloom comes with the warning that if it not returned to the Valley of the Ten Peaks, it will undo time and reality completely. To make matters worse, the group is tracked by a group of girls with guns. How will it end?
25: The Characters are in a submarine that is heavily damaged and heading towards a deep trench at the bottom of the ocean. To make matters worse, there are some undead creatures on board that have their scent.
26: The Characters exist in a world run by animals doing everyday tasks and jobs that humans would do.
27: Cantinas and Customs: The Characters are in the wild west, but instead of everyone riding horses everywhere, they are replaces by roadsters and muscle-cars . Make sure to make reference to models that are named after horses , i.e. Mustang, Charger, Colt, etc.
28: The Characters are inmates at an insane asylum, and they have the ability to jump into another world of their combined imagination. What that world is, and the part that they play in that world is up to them.
29: A former rockstar turned mad scientist has developed a Dubstep Bomb, a creation capable of disrupting temporal flow if detonated. The Characters are all powerful rockstars who are called in by the Gods of Rock to stop the evil rock genius.
30: Ancient Greece: the Characters are summoned to appease Zeus. Is Zeus in a jovial mood, or does he demand toil from the group?
31: The Characters come into possession of Alien Technology that will make them rich and famous if they figure out a way to make it benefit all of mankind. The problem is that everyone wants the technology, and the group is being hunted down from all angles.
32: The Characters are stuck deep in a jungle with rival tribes all around. There are wildfires raging around the perimeter of the jungle, making escape impossible. To make matters worse, one of the tribe tells the group that there is a war being raged between one tribe's Jungle God and the other Tribe's Lake Wizard.
33: A super villain gadget maker has made multiple clones of himself, each with at completely different power set than the original. Are our intrepid superhero Characters up to the task to take down this multiple menace?
34: An undisclosed plague has forced the quarantine of the city in which the Characters reside. The plague is caused by an alien syndrome of some sort. Its effect upon the general populous is up to you.
35: the Characters are trapped within the confines of a maximum security facility. There are numerous traps and pitfalls the characters need to overcome before confronting the person or persons that hold them in the place.
36: The Characters are involved in an alternate time-line of World War II where the enemy is using alien technology from its alien allies. Luckily, the group's side has some weaponry of their own that is almost ready for testing.
37: Ghost Towns and Gold Rush: Characters are part of the California Gold Rush, but there is something sinister in those nearby hills that wants their stake in the claim.
38: the Characters are employees at a burger joint when a higher power calls them into action to save existence as they know it. They will have to fight a great adversary on another plane, but the adversary also has its own set of defenders...doppelgangers of the group.
39: One of the American Artifacts has gone missing or has been stolen, and it is up to the Characters to try and find it. The Historical Preservation Society that the group works for has a few tricks up its sleeve and will allow the group to borrow a few items that will help in the retrieval of the item.
40: The Characters are nomadic warriors in a savage land where they come across a village that is facing an outside invader. The group feels compelled to help the villagers and stop the spread of evil.
41: The Characters are hired muscle by the king in the land, and has summoned the group for the sole purpose of collecting taxes. Those who fall under the king's rule are not happy about this and will resist.
42: The Characters are vice cops with fast cars, hot women, and smooth moves. The group has to solve a major crime before someone gets killed.
43: The Characters are all teens who have decided to spend a weekend at an abandoned farm house, complete with barn, forest and lake shore. They are completely isolated from the outside world, and someone, or something, is stalking them in the darkness.
44: The Characters are stranded on a deserted island from a shipwreck. There are strange occurrences on the island from time to time, and nothing is as it seems.
45: The Characters are fratboys looking for a party. Something completely unexpected happens. The group is the only one who can deal with this odd situation.
46: The Characters are a group of quirky teens who go around solving crimes in small towns. It all fun and games until their van breaks down in front of a large abandoned mansion. Something calls to them from within the depths of the house.
47: The Characters think that they have seen a cryptid somewhere in the city. They feel the need to track this creature and find out the truth behind the sighting.
48: The Characters are members of a deep space rescue team. They are sent out to a remote world where a distress beacon has been activated. The world is inhabited by animal hybrids.
49: A natural disaster has leveled the Characters' hometown and turned it into a wasteland. No one is coming to help them, and now its every man for themselves.
50: An alien invasion that seems more comical than scary befalls the Characters and their home world. There is some ridiculous way to stop the aliens, but can the group find it in time?
51: The Characters are archeologists who are working on a dig site deep within the amazon jungle. The local tribe warns them about a pig-faced demon who is rumored to walk between the worlds at the dig site. When one of the group's associates goes missing and the characters find half-chewed remains, tensions mount.
52: The Characters are assaulted by a colony of underground dwellers who have taken something/someone of value to he group deep into their lair.
53: Guns. Mutants. End of the world. Go.
54: The Characters are in Boston at just about the end of the 19th century (1890's) and it appears that someone is pretending to be The Ripper stateside.
55: The characters are professional wrestlers and pro-wrestling is completely real. All gimmicks and angles are a daily part of their lives. Things are good until a rival federation invades their company and kidnaps the chairman's daughter, taking her into “Parts Unknown”
56: The Abyss opens, and Hell's fury is unleashed into the world. The Characters are summoned by The Vatican and have to take up arms against this diabolical evil. They are the chosen ones to fulfill the prophesy.
57: The Characters are sucked into an RPG and are forced to play themselves. Can they both defeat the game and find the way out?
58: The Characters are each a Video Game Icon and are called into service by a master computer to defeat a dreadful new boss.
59: The Characters are high powered swords for hire who get dragged into a war between two kingdoms. There is much slaying.
60: The worlds most beefy soldiers are sent behind enemy lines to stop an evil dictator's quest for world domination.
61: An ancient entity that is beyond the comprehension of man threatens to break into the Characters' world with the help of some cultists.
62: The Characters are Epic Level heroes of fantasy, and they are attempting to take down a roving band of air pirates who are attacking villages with their air ships and burning them to the ground.
63: The Characters are pirates being hunted by the Royal Navy, and the group is attempting to get their riches.
64: The Characters are monsters in the graveyard, getting ready for a party, but a roving mob of humans attempt to crash the party.
65: The characters are all monsters and in high school, but something is causing the students to turn into humans.
66: the Characters are stuck in a dream-like world, held there by a task that needs to be done before they can return to reality.
67: the Characters are adventurers deep in the jungle, looking for an ancient legend and following the clues of centuries past.
68: An ancient civilization is unearthed, and its inhabitants resume life as if nothing has stopped them for the last several hundred years. The new people face turmoil and bigotry at every turn. Somehow the characters are involved with this, either being part of this new civilization, or members of the current civilization.
69: the characters are astronauts and are sent to a planet to look for life and scout the terrain. They are not alone.
70: a mega-fortress flying in the sky is sending down it's homespun forces. Can the characters stand up and fight these things?
71: The Characters are in a magical world where ponies shoot lasers out of their eyes, and magic is all around.
72: A giant plant makes it home in the town in which the characters reside. It is carnivorous and begins to take people deep into its lair. It is highly intelligent and twice as cunning.
73: The Characters are paranormal investigators sent deep into the bayou to find a small town that been overrun by alligator men.
74: The Characters are heroes set in an 8-bit world.
75: The Characters are drivers who are competing in a transcontinental race. Sabotage and debauchery a plenty.
76: Each of the Characters are vying for the throne for a dying emperor in a pseudo-feudal Japan setting.
77: the Characters are monster hunters, and their small town is being attacked my monsters of all shapes and sizes.
78: The Characters are sent back into time to prevent a major catastrophe from occurring, before they themselves become part of the past.
79: The Characters are vacationing on a cruise ship, when it is attacked by Somali pirates.
80: the characters are a special ops squad sent into the deepest parts of Africa to take down an elusive Warlord. They may need to do some major dirty work to get the info that leads them to their target.
81: The Characters are members of a vampire society, and one of their members has died by questionable means. The group has to break into the morgue to get the body back before the truth about vampires is revealed.
82: The characters have to do battle with an evil carnival that has the town in its grasp.
83: The Characters are stuck in a factory with an evil Willy Wonka.
84: The Characters have to travel to the realm of the dead to bring back a loved one who has been taken before their time.
85: The characters are barbarians who have to restart their village and begin anew. They have to be cautious of other nomad clans who may attack at any time.
86: The Characters are aliens that participate in a bloodsport/ deathmatch that is the most popular show in all the universe.
87: The Characters are on a TV game show that allows them to act out their deepest and darkest desires. There are sinister repercussions if they lose.
88: The Characters are tracking down a dangerous serial killer as he travels through time.
89: The Characters are tracking some sort of vicious creature in the depths of the sewers.
90: The Characters stumble upon a mega-corporation's secret underground facility. They are captured by security, and now they are possible test subjects for a new experiment.
91: The International Lip-Synching Competition is cut short by a on-stage murder, and the Characters are called in to attempt to solve the murder.
92: Mimes vs Clowns. Things could get ugly.
93: The Characters have to get through a dark labyrinth to save their companion.
94: The Characters are on a reality TV show, and the next door group of crazies aren't too happy about it.
95: A tome that has ancient magic is hijacked and stolen from the back of a big rig in the desert.
96: The Characters are locked into a museum after hours. Crazy and often disturbing events occur.
97: An old man and eccentric toy maker has passed away, and in order to collect the inheritance he has left the group, the group has to spend the night at his old creepy mansion.
98: The lost treasure of the Incas hold unimaginable power, and dangerous relics from a world long gone.
99: The Characters fall into a deep pit, survive, and have to deal with dinosaurs.
100: The Characters are trapped in an old Victorian mansion, where every door leads to another plane or dimension.
101: if you've had to come this far for a story hook, then this is the last offering I have for you. The Characters are summoned by a deity after their deaths. They are given a second chance at life and resolution. They are told they have to find “the fabled tasty treats of the Ghouraan” which they will need to plane jump to several locations to get each ingredient and prepare the treats for themselves.