I often run my tabletop RPG sessions completely improvisationally, starting with a single encounter idea and no other preparation. I just riff from there. Here are 7 single-encounter adventure hooks I've used repeatedly throughout the years for this. I hope you find them helpful!
1. Thieves in the abandoned hillside house
While traveling to the big city for a festival or some other event, the camping party is robbed at night. They wake to find several of their valuables gone. A poorly concealed trail leads to a decades-old doorway in a nearby hill. The first chamber within the abandoned hillside house serves as a makeshift lair for a pair of thieving ophidian humanoids. If the party can defeat the pair and recover their valuables, will they choose to explore deeper into the hillside?
Tips for running this hook:
- Pick a humanoid stat block for the ophidians that will give the PCs a challenge. For example, for early-level PCs you might use orcs, for mid-level PCs you could use trolls, etc.
- Think about how the ophidians should react to the PCs attacking. Maybe they are willing to die for their stolen goods. Maybe they would offer additional treasure to avoid a fight. Do they know something about the hillside house they might barter for mercy?
- Make up a reason why the ophidians decided to stay in just the entry chamber. Are there traps beyond? Is there a nastier creature that scared the ophidians? Is the house haunted?
2. Transporting a dangerously unlucky heirloom
The party is hired by a wealthy family to transport an heirloom to a nearby town where the family's black sheep was recently sent in shame. The matriarch warns that moving the heirloom might be dangerous. Generations of family stories tell of tragedies befalling caravans carrying the unlucky heirloom, all under strange circumstances. During the first night on the road, the party is assaulted by an invisible assailant slashing at them with an unseen blade. If they survive the first night, what danger awaits the next?
Tips for running this hook:
- When the attack starts, don't immediately tip the party off that it's an invisible assailant. Start with things like "as you sit at the fire during your turn at watch, pain suddenly burns at your chest, and you look down to see a large gash starting to bleed." A great part of the fun of this encounter is seeing how the players react to not knowing what is happening.
- Make up a reason for why the invisible assailant is assaulting the party. Does it want to take the heirloom? Does it merely want to harm or kill those who have it? What is the relationship between the invisible being and the item?
- Put an interesting constraint on the assailant that draws the encounter out over the journey. Maybe it can only affect the physical world for a few moments (e.g., combat rounds) per day or night, meaning it must depart before it can strike a killing blow. Maybe it only materializes when the heirloom is visible.
- After the first night of direct assault, have the invisible assailant try something more subtle the next day. For example, the party is attacked by a pack of dire wolves because the invisible assailant secretly placed an herb in their packs that attracts and frenzies wolves.
3. The mysterious overnight pit
While the party is visiting a small town, chaos erupts after a pit opens mysteriously in the night. This pit, in the center of the town's green, has paved walls and a spiral stair descending down. It is clearly the work of magic; it could not have been dug or built overnight. The pit's bottom appears to be a study or office full of furniture and a closed wooden door. Once the party descends into the pit to investigate, a desk (actually a mimic) attacks! How did this pit arrive? Who or what is behind it? The answer lies beyond the door.
Tips for running this hook:
- Don't have the mimic attack any ordinary townsfolk that descend to the study. This mimic feeds on magic and power. It will only attack a magic-using PC or one with a magic item.
- Use what you know of the PCs to entice them down. If they are motivated by treasure, add something valuable. If they are motivated by magic, add a magic item or spellbook. If they are motivated by power and fame, have one of the PCs recall a bard's tale about the pit.
- Make up who owns the pit and why they move it around. Two examples from my own improvisation include:
- The pit is actually a descending tower that simultaneously exists in multiple places at once. Its owner is being held hostage, so he "moved" the castle to the nearest place he sensed heroes. In this case, the mimic is just an overzealous house member that will stop attacking if the PCs will just talk to it and explain they have good intentions.
- The pit is a honey pot that is magically moved around by a mad mage to lure in adventurers for fun or profit (or both!). I used it this way with Halaster in an Undermountain campaign to pull the party into the megadungeon from the Dalelands.
4. A loved one goes missing
One of the party member's siblings has gone missing! They were last seen in a seedy pub they had no place being, talking to a known thug in the local thieves' guild. It's a classic kidnap and ransom setup, and the ransom is that the party must break a prisoner out of a nearby town's jail for the guild.
Tips for running this hook:
- There should be something the party is missing. A few angles I've used are:
- The sibling has been secretly dating the imprisoned guild member and hasn't actually been kidnapped.
- The sibling is the one imprisoned, in disguise, and has been working for the guild for years.
- The guild isn't actually involved at all. The "thug" and the sibling work for a secret society (I used the Harpers in the Forgotten Realms) and need help breaking one of their agents out of a corrupt constable's jail.
- A fun thing about breaking someone out of jail is there are so many different ways to go about it: brute force, deception, stealth, magic, a con, etc. Whatever way the PCs choose, give it a chance to be successful, but also add some complications to make it interesting.
- If the PCs try to "go to the cops" to get help, have the constable they go to be on the take. They let the PCs know if they try anything like that again, "you won't ever see your brother or sister alive."
5. Chasing the baby dragon
While traveling along a wooded road, the party spots a very juvenile dragon flying above, carrying a goat and a sack full of gold. The goat's terrified bleating indicates the dragon's lair is nearby, and the party has little trouble following the sound to find it. As they make their way into the lair, whether to steal the gold or attack the dragon, both vanish suddenly. The party finds themselves instantly trapped inside a steel cage! The dragon and its gold were an illusion made by an old troll witch, meant to lure adventuresome travelers to her cage where she can hear their stories before eating them. How might the party escape?
Tips or running this hook:
- The witch will claim to just be interested in stories and won't mention eating them. She will promise to free them after they tell her some interesting adventuring stories. She is lying and will not keep her promise. She will eat them.
- There are a number of ways the PCs might escape the witch: bartering with her, tricking her, finding a way to open the cage and escape, fighting her when she goes to eat them, etc.
- If the party manages to kill the witch, find some way to build off this initial encounter. Maybe they find personal belongings among the remains of her previous victims to return to a nearby city. Maybe she curses them before dying, leading to new troubles.
6. Taming a magical mount
A famed adventurer visits town riding atop a magnificent, magical horned creature none have seen before. For the cost of a few drinks, she tells the party the secret to finding the creatures and to taming them, leading them deep into a distant forest where they must survive a far less friendly creature first.
Tips or running this hook:
- The famed adventurer will only tell the party where to find the magical mounts if they promise to treat them well and not tell others. If she learns the party has lied to her, she returns to "correct her mistake."
- Make up what the "far less friendly" creature is. I have done: poachers from town that follow the party and attack as soon as the creatures are in view; a giant serpent that is tired of humans entering the woods and taking its food supply; the trees themselves, animated by druids to protect the magical mounts from predators and poachers.
- Have the famed adventurer meet the party on the road after they have secured their new mounts to tell them "something she forgot to mention," like:
- The mounts must be fed a fruit that only grows in their home forest, meaning the PCs either have to make regular visits back to the woods, or must find some other food they will eat.
- The mounts frenzy on the full moon, attacking anything and everything in their path.
- A sect of druids protects the flock of creatures, and might now decide to track the PCs down so they can return the creatures to their home.
- Make up a reason for why the famed adventurer told the party about the magical mounts. Is she trying to put the sect of druids onto someone else? Is she looking for breeding stock for her own mount? Does she need muscle for an upcoming adventure and wanted the PCs indebted to her?
7. Bring your sage to work day
A renowned sage is offering for sale the location of a powerful magic weapon. The information is affordable but comes with a catch: the party has to accept a geas to bring the sage along and safely bring him home. He complicates an otherwise simple trip to loot a lair.
Tips or running this hook:
- Decide what makes the sage difficult to bring along, and play it up. Is he annoying? Is he clumsy? Is he unlucky? Does he want unreasonable accomodations?
- Make up why the sage wants to accompany the PCs when they go after the loot. What is he not telling them? For example, one time I used this hook, the sage wanted to make a detailed sketch of a beast no other sage survived trying to sketch, and actually snuck the magic item into the lair while the beast was hunting to set the whole thing up.
- Try to endear the sage to the PCs so you can use him for new, future adventure hooks and establish a long-term relationship with the party.