Dungeons & Dragons will see players go through all sorts of underground environments, from treacherous mines to sunken kingdoms. But what happens when your players are sent to go spelunking in a cave? A cave can come across as a pretty plain environment, with it either being too small so that the party find their objective right away, or too big and so it gets repetitive to traverse through. If your players aren't the roleplaying type, then some encounters are definitely needed.
Though caves aren't exactly like a unique dungeon with traps and treasure, they can still be great places to take your game. So here are just a few encounters that can really spice up an underground adventure.
10 A Court Of Trolls
One of the best parts of modern fantasy is the deconstruction of "hostile fantasy races", the idea that orcs and trolls are just bad guys to be dealt with. It's led to some more open and exciting possibilities when it comes to these creatures, and nothing is better than to get a peek into their lives, whether it be through an NPC or an encounter in some dim-lit cavern. This encounter is a perfect example when the players stumble across an active court case... but with trolls.
Obviously being in a cave because they wanted some privacy (or perhaps in troll society, caves are just like buildings to them), it could be fun to see two trolls representing themselves to some sort of troll judge. Perhaps it's a messy divorce, or a case about the alleged robbery. But regardless, the court could always use a jury, and that's where your players can come in.
9 The Last Dragon
Many ideas in D&D can range from silly to serious. A vampire can be a fun-loving NPC who is overly friendly to the party, or a menacing antagonist like Strahd who will duel the characters in an epic battle. This is one of those encounters where the idea can be moulded by you to set the tone when the party comes across a dragon in the cave. But it's not just any dragon, it is a child dragon that is left to defend a small hoard of gold with a couple of tempting magical items around.
What the party decides to do, whether leave the dragon be, try to fight it, or even attempt to adopt the dragon, is up to the party. But this could be a fun tale of a young dragon left to look after a hoard for a while, or something sadder about a dragon who has lost its parents and is now alone.
8 It's Free Real Estate
When players see the glow of campfire light in a cave, it can usually be associated with bandits they're about to do battle with. So it would be surprising to throw an encounter where the party meets a camp of unhoused folk living in a cave. Perhaps with tents, torches and some magic, they have turned the cave into a cozy spot to shelter from the elements.
This is a nice spot for if players have to go further into a cave and need a place where they can rest without worrying over a foe finding them. As well as this, it's a nice way to introduce some NPCs and keep things lively if the players aren't talking much.
7 How Ozymandias Of You
Caves can lead to all sorts of interesting places, dungeons, cave systems and just maybe the ancient ruins of a begotten empire.
Perhaps it's part of an old Dwarven city that caved in and was lost to time, or maybe it's just a ruin that was caught in a sinkhole and ended up here. The players are then free to explore the ruins and uncover a story of a long-lost empire, while also able to use the ruins as a landmark for their exploration.
6 The Trapped Teleporting Wizard
Magic is a fantastical thing in a lot of fantasy lands, but it can also be the source of much mayhem, which is the case here for an unfortunate wizard the party may come across. Come up with a wizard NPC that suddenly teleports in during the party's travel and gets stuck underneath a rock, or in some crevice, and could use the party's assistance.
Of course, with the Teleportation spell, there can always be mishaps which send your party into the wrong place as well, opening up all kinds of story hooks.
5 Wait, Is This Prophecy About Us?
This is the kind of encounter that is more environmental storytelling that would require you to have a party that loves to roleplay. Have the party stumble across ancient cave drawings of the magical kind that hints that somehow, the carver knew the party would arrive in this particular cave. Mention some of the previous events in your campaign to show the carver knew of their entire adventure to spice things up.
Either way, this is a great way to have the party actually get to talking, and to introduce a prompt for roleplay without it feeling too forced. It allows the party to ask questions about themselves, the caves, and just who – or what – came up with the prophecy.
4 Out Of All The Caves, You Had To Pick This One
A fun thing about caves is plenty of things can be lurking in the shadows, from animals, to dragons, to even hardened criminals who wouldn't want the party knowing of their whereabouts. This is good for a cave near civilisation, as the party happen to run in on a band of criminals who have just escaped from prison.
Though there is the opportunity to talk them down if your players are the more diplomatic type. However, these people have just finally gotten their freedom and likely won't take the chance of it slipping away from them again if some strangers tell the guard.
3 A Fungal Infestation
If you're worried about the cave itself being too boring, then look no further than to fungus. Instead of having the cavern be nothing but rocks and stone, throw in a fungal growth of mushrooms, vines, and other plant life that has spread throughout the cavern, and then make them sapient. Perhaps speaking Druidic, Sylvan or some other ancient tongue, communicating telepathically.
Whether the fungal system is a friend or foe is entirely up to you, and the challenge you wish to give to the player. But we'd recommend that it be neither, just a neutral entity that will grow hostile if the party ends up destroying plant life or the cave it calls home.
2 Captain Arcana
A fun thing to do when you're stuck for ideas is to let yourself be inspired by other media.
For this encounter, you can look at none other than the star-spangled superhero Captain America for inspiration, as the party come across what looks to be a malfunctioned Clone spell. Inside a crystal container of salt water is the body of a physically fit warrior. If unsealed, then they will awake the body of a Bladesong Wizard who was supposed to awake years ago, but instead has been comatose as their container was damaged.
However long they've been in there is up to you. But the players may come across a character out of time who needs some gentle coaxing and can wait by the cave for the party, creating a potential future adventure if they'd want to follow it up after their affairs in the cave.
1 Rocks Fall, Hopefully Nobody Dies
When all is said and done, there are few things more exhilarating than a close shave with death. Triggered by combat or a devious explosive trap, things go south for the party when the cave begins collapsing.
They can rush out, but perhaps there would need to be some skill challenges in order to show who can get out, and who potentially gets trapped and needs to figure out another way out.
Either way, this is a fun way to end an adventure, or it can be easily adjusted, so you don't kill off your players or trap them in a grisly situation if you don't want them to. Sometimes a collapsing tomb or mine can just be the perfect thing to split up your party and allow your players time to develop specific relationships within the group.