One-shots are a great way to introduce new players to Dungeons & Dragons or other RPGs, and to give experienced players a chance to try out new characters or builds. When designing a one-shot, we recommend you start with a great villain, and end with an epic boss fight. But what about the middle? What goes into generating brilliant encounter ideas for a DnD or other RPG one-shot?

In this blog post, we’ll take a look at some advice and ideas for creating encounters to challenge your players and keep them engaged for the whole session. When preparing encounters for a one-shot, it’s important to keep in mind the following:

Keep the encounters short and to the point. Players should be able to complete them in a few rounds. This is important because one-shots are usually shorter than regular campaigns, and players don’t have as much time to explore and get sidetracked. If the encounters are too long, players may start to get bored or feel like they’re not making progress.

Make the encounters challenging but not impossible. Players should feel like they are in danger, but also like they have a chance to succeed. The encounters you choose should be appropriate for the party’s skills and abilities. If you’re playing Dungeons & Dragons, the Dungeon Master’s Guide has tables for calculating the difficulty level appropriate for your party. This goes beyond level and XP to party composition. Think about what the party is good at and where their weaknesses lie. If they’re all spellcasters, you might want to include encounters that are challenging to solve with magic. Encounters force players to spend resources like spell slots, potions and ammo. When they reach the boss fight, it should feel like the last push of a long journey – creating a more dramatic ending, and a more satisfying one-shot.

Make the encounters relevant to the story. The encounters should help to advance the plot and move the players closer to the final confrontation with the villain. The encounters should also fit the setting. If it’s set in a dungeon, you might want to include some encounters with traps and monsters. If it’s set in a city, you might want to include some encounters with NPCs and social challenges.

Make the encounters fun. Players should enjoy playing through the encounters and feel like they are part of an exciting adventure. This is important because one-shots are often an introduction for new players, and they may struggle to keep up and stay engaged. One-shot encounters should represent the best aspects of the game in a bite-sized package.

Vary the encounters for different playstyles and PC strengths. There’s always one player who loves to roleplay, and another who just wants to deal huge amounts of damage! Try to balance your encounters to give everyone a chance to shine. When you know the players at the table, this is pretty easy. If not, remember to include 1) some puzzles or information-based challenges for the thinkers, 2) some fun battles for the doers, 3) some roleplay encounters for the drama queens, and 4) some traps (or something else) for the rogues to play with!

Building Encounters for your DnD oneshot

Great encounters have three parts. A Location, the Goal of the PCs, and the Obstacle they must overcome. In fact, the formula for a great encounter might look like this:

In LOCATION, the characters seek PROGRESSION but must overcome OBSTACLE.

Let’s break that down.

Locations: Where is the encounter happening? This will depend on where the rest of your adventure is set. For noir adventures, it might be a back alley, a basement, or by the docks. For a high fantasy adventure, it could be the room of a dungeon, an abandoned ruin, or a cave. There’s a lot of opportunity to add flavor and world lore. Add a few details that make your location special, and dig into the senses to make your players feel immersed.

Progression: This isn’t a random encounter – something has led your players to this location, and that something will progress the story. Are the party here to chase down a clue, retrieve a stolen item, interrogate a suspect, or rescue an NPC? In the case of dungeon encounters, the progression is often physical – the party is trying to travel through this location to the inner sanctum where the villain is hiding.

Obstacle: whether monsters, traps, a hard-slog through difficult terrain, solving a riddle, unlocking a box, or an uncooperative NPC, the progression shouldn’t come too easily. Obstacles are things your party need to overcome to achieve the progression. Presenting a variety of obstacles gives different party members a chance to shine, and helps keep the story fresh. This is the only one you should double up on – several obstacles in a location is valid! For example, an uncooperative NPC may also summon monsters to defend themselves.

If the party fails, there should always be ANOTHER way to Progression (albeit with resource, time, condition or even curse-style cost). After all, you don’t want a locked door to end the adventure!

As a general rule, for a one-shot, 1-3 of these scenes are plenty. Keeping the locations close together to limit travel time and scale is a good idea too.

For example:

In CAVE players seek THE LOCATION OF VILLAIN’S LAIR but must overcome ACID CAVE SLUGS.

In VILLAIN’S LAIR ENTRANCE players seek ENTRANCE TO THE LAIR but must overcome A RIDDLE TO FIND THE DOOR

In VILLAIN’S LAIR players seek to PROGRESS TO THE VILLAIN’S THRONE ROOM but must overcome HORDES OF HENCHMEN.

For an adventure designed to take several sessions, this formula can easily be extended by adding more locations, progressions and obstacles. For example, each major progression point might require a small dungeon or larger encounter. If you’re trying to extend the adventure, including travel between locations, with some optional encounters, can help (although it’s always a good idea to theme these to your story and setting).

And if you’re looking for side adventures, Locations can spawn interesting side quests. For example, as well as the villain’s henchman, there’s also a ghost in this dungeon that wants to be freed, seven pieces of an ancient amulet, and a secret room that reveals a mysterious carving.

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More encounter ideas (DnD / RPG):

Here are some ideas for encounters that are closely tied directly to the main plot:

• Natural creatures driven mad by the villain plot: The villain could be using magic or technology to drive animals or plants mad, or it could be a side-effect of their plot. Perhaps the players encounter these creatures in the wild, or they’re used by the villain as guards or traps.
• Henchmen sent by the villain to prevent meddling: The villain may send henchmen to stop the players from interfering with their plans. These henchmen can be anything from common thugs to powerful mages.
• Outraged villagers who think the party is responsible: The villain could be framing the players for a crime they didn’t commit. The villagers might attack the players on sight, or try to turn them over to the authorities.
• Competitors for the prize: Perhaps the quest-giver has set two parties against each other to defeat the villain? That means not just enemies, but competition! How will the parties deal with each other? Will they combine forces, or try to wipe each other out?
• Difficult, dangerous terrain lies between them and the villain: The players have to cross a dangerous mountain range, a swamp, or a desert to reach the villain. The terrain could be full of obstacles, such as cliffs or quicksand which require skill-checks to pass, or simply more monsters!
• A puzzle or riddle must be unravelled for direction: The players find a puzzle or riddle that will give them a clue as to where the villain is located. The puzzle could be a simple one, like a riddle, or it could be a more complex one, like a maze. It may not even be intended as a puzzle – for example, an exotic or ancient map that requires deciphering, or an old song which must be interpreted to find the ruins it describes.
• An object or key must be obtained to progress: The players could need to obtain an object or key to progress through the adventure. The object could be a magic item, a totem, or a simple key.
• Information must be gained to understand (how to defeat) the villain: The players may need to gather information about the villain – who are they, where are they, and what are they planning? This information could be obtained from NPCs (interrogating henchmen or questioning witnesses), from studying the villain’s behavior, or it could be found in the villain’s lair. In magical worlds, remember that higher-level players have access to spells like Divination and Commune (allowing them to gain information from divine beings), and even Telepathy – so be ready for what your players might fling at you!

A note from Janet on DnD puzzles and information-clues

When using puzzles or information, don’t set difficulty too high if it’s the only way to advance the story. No matter how simple the solution seems to us (the GMs and designers), your players may not get it – and you don’t want them stuck on one side of the puzzle door for three hours because they couldn’t solve the riddle!

Prepare plenty of clues, but only mete them out if the players seem stuck. You can prompt players to roll Knowledge, Perception or Intelligence checks (whatever works for the system you’re using) and reward the highest rolling (rather than giving a strict DC). This means that the party still gets the info regardless.

For puzzles, one of my favourite tricks for this is a “One-Two-FAIL-FORWARD” mechanism. They get two tries and on the third, if it’s still wrong, something dramatic happens which causes the party a penalty, but allows them to progress. You can also trigger this if you sense your players are getting too frustrated or losing focus. For example, the puzzle door explodes, causing damage, but they can move forward through the dungeon. Or a different door slams open and 2d4 golems swarm out – but once they’re defeated, the players discover a secret passage in the room beyond that leads them onward.

Still stuck? Here are even more one-shot encounter ideas (DnD or other RPGs):

• A combat encounter: Tried and true, the players must fight off the villain, or some of his minions. This could be in a dungeon, in a forest, or even in the middle of a city. Varying the setting and the enemy’s powers is the key to bringing variety here. Try adding a bard, cleric or necromancer to your mooks for some variety. Remember that when overpowered, mooks may try to escape, which brings us to…
• A chase scene: The players must chase down the villain or his minions, on foot, in vehicles, or even through the air. Using control elements (spells like Haste and Slow), difficult terrain and, in cities, local knowledge to provide short-cuts, can add extra dimension.
• A social encounter: The players must interact with an NPC to progress through the adventure. This could be a friendly NPC, like a shopkeeper, or it could be an unfriendly NPC, like a guard or even a captured henchman. If this is critical for your adventure, and you need the players to discover something for the story to progress, have the NPC hint at something “by accident” to move the plot forward.
• A skill challenge: The players must use their skills to progress through the adventure. This could be a challenge that requires acrobatics skills to jump across a chasm, lockpick to get through a door, sneak to bypass the watch, or simply persuasion skills to convince an NPC to help them.

The possibilities are endless, and you can tailor the encounters to your own specific campaign. Here are some final tips for creating encounters for a D&D one-shot:

• Use a variety of monsters. Don’t just throw a bunch of goblins at your players. Mix it up by using a variety of monsters with different abilities and challenges. Use swarms, tricksy monsters with weird powers, flying monsters, invisible monsters, and waves, to create variety. Just remember – a theme that ties your one-shot or adventure together will make the thing feel cohesive. So if the theme is undead, dive into zombies, shades, ghouls and vampires. If the theme is fae, explore all the different types – or even make your own RPG monsters!
• Use the environment. The environment can be a powerful tool for creating challenging encounters. Use the environment to your advantage by placing hazards, obstacles, leveled, moving or difficult terrain, and traps in the way of your players. Again, this is a great place to bring in your themes. For example, if you’re underground, use rivers of lava, fields of jagged crystals, narrow squeezes and cave-ins to create hazards.
• Don’t forget the roleplay. D&D is a game of imagination, so don’t forget to add roleplay to your encounters. Give your players a chance to interact with the NPCs and the environment in a meaningful way.

Have fun! The most important thing is to have fun. If you’re not enjoying yourself, your players won’t either. So relax, let loose, and have a good time!

💡Ready to get started? Download this great printable one-shot worksheet from our founder, game designer Janet Forbes.

🛠️Looking for a complete DM/GM toolset, compatible with over 40+ RPG systems, including D&D 5e, Pathfinder, and Call of Cthulu? Create a free World Anvil account.