Saturday, May 11, 2024

Deconstructing Random Encounters (+ Spirits of the Underworld)

If you're not interested in theorycrafting you can skip to the Spirits of the Underworld section, which is hopefully immediately useful to your game.

This time I'm not looking at how we determine when random encounters happen (Underclock), I'm looking at what sort of things we can encounter.

I call it deconstruction but really I'm just going to look at the assumptions/tradition for random encounters, then talk about the gap between what we want them to do and what they actually do.

Types of Random Encounters

Traditionally, random encounters are limited to 2.5 types.  (1) Monsters that attack you, (2) NPCs that you talk to, and (3) Environmental effects like gusts or rattling chains.  (If you use reaction rolls, (1) and (2) can blend together.)

The Purpose of Random Encounters

#1 - To create time pressure.  Random encounters need to be threatening so that players feel some urgency in the dungeon.  Without time pressure, they'll just use pickaxes to mine through all the walls.

#2 - To make the dungeon feel alive.  When a room is exactly the same each time the players visit it, it makes the dungeon feel dead or static, like a video game.

#3 - To provide some randomization.  It can push the game in a new, unexpected direction.  Randomly generated encounters can sometimes be better than published content because generating content live forces the DM to integrate the encounter in the pre-existing world.

There are downsides to random encounters, too.  Improperly deployed, the can feel disconnected from the site and the setting.  They can feel like wastes of time, or they can strain belief.  

Time Pressure

A lot of Neo Trad games seem to do away with time pressure altogether (no tracking torches, food, ammunition, random encounters) except for spell depletion.  But this is expected--the focus is on the encounter and the story, not the dungeon.  But we're going to focus on OSR dungeoncrawling, where time pressure is very prominent.

We can actually do all sorts of things to create time pressure.

A lot of the overloaded encounter dice I've seen have some version where they mix different pressures together: torch depletion, spell depletion, food depletion, etc.  Other systems have torches, etc deplete at a fixed rate, but the overloaded encounter die shows that you can have other time-based depletion moved to a die roll.  (You can have a meaningful dungeon crawl if strict time records are not kept.)

The Underclock is also designed around putting visible time pressure on the players.

You can also leverage the real-world time to create time pressure.  Some games have the requirement that the party must finish the session outside of the dungeon.  Shadowdark torches only last 1 real-world hour.

If you think about it, the average dungeon crawl usually has at least 3 types of time pressure going on simultaneously.  I guess the lesson here is that it takes lots of small time pressures to motivate the players sufficiently, but I wonder if you couldn't achieve the same effect by having a single, major form of pressure.

Other ideas for time pressure:

1. This dungeon only has a single monster that hunts you (e.g. Alien: Isolation).  Instead of random encounters, the monster shows up.  The party will have to hide.  Hiding spots cannot be re-used.

2. One enemy that increases it's attacks.  The kobolds periodically launch attacks at you.  Each time, 1d6+X kobolds show up, where X is the number of hours that you've been in the dungeon.  After 2 hours, their ranks include kobold shamans.  After 4 hours, they bring cockatrices.  After 6 hours, they bring a (nearly uncontrollable) umber hulk.

3. Sanity or stress.  Anything that grinds down on players.  It doesn't even need to do much--just seeing a number drop on your character sheet can be discouraging.  Maybe you enter the dungeon with 100 Sanity and lose 1d6 Sanity after every random encounter, with bad things happening at 60, 30, and 0 Sanity.

4. Equipment degradation.  Every time a random encounter is rolled, each metal item the PCs carry has as 1-in-6 chance of rusting away to nothing. 

5. Goal depletion.  The cultists sacrifice the villagers.  The dragon eats more hostages.  The rival adventuring party steals some of the loot.

6. Rising Water.  When the party opens the door to the dungeon, water starts flowing in.  Every encounter check, the water gets 1 foot higher.  The ceilings are only 8 feet high, and encounters get more difficult the higher the water is.

7. Spirits of the Underworld (see below).

Stat depletion, lose spellcasting, mutations.  I could go on.  Remember: attack every part of the character sheet.

Reinforcing Versimilitude/Realism

We want the dungeon to feel like a living, breathing place.  We don't want rooms that are just "5 orcs standing around waiting for the players to show up".

Random encounters traditionally help with this, especially when you eschew generic wandering encounters "2d6 kobolds" for bespoke ones "2d6 kobolds from room 15 hunting the quark from room 29".  However, we can probably come up with some alternate ideas.

1. Temporal Cycles.  You've seen these before.  

The guards patrol this gallery every day at 4pm.  

The mushroom people forage by the river at night.  

But you could branch out a bit more.  

Every day from 11am to 1pm, the sun hits the solarstone in the center of the dungeon, illuminating all of the crystal-walled rooms.  No shadow-worm encounters will occur during that span.

2. Time-linked Events.  Once the players do a thing, something else starts to happen on a schedule.  Best to make this visible to the players.  

Once the players enter this room, they are spotted by the kobold lookout, who runs back into his tiny escape tunnel.  A kobold war party arrives in this room 10 minutes later.  Add kobold war parties to the random encounter list.

Immediately after the Door of the Sea is opened, 1" crabs start to flood into this room.  The next time the players come to this room, it has been populated by 2d6 giant abyssal crabs and a Panoptic Tentacle.

3. Scripted Events.  (Honestly, these shouldn't be a sin, even in an OSR-setting.  Random rolls are one of the best ways to make a dungeon feel alive, and I'm not proposing that we drop them, I'm just saying that random rolls don't need to be the only tool we use to make a dungeon feel vibrant.)

The second time the party enters this room, they will interrupt 2d6 painted men from Level 2.  The painted men are busy transporting the Obelisk of Forgotten Memory back to their tribal encampment. 

The first time the party enters this room, it is empty except for water trickling down the walls.  The second time the party enters the room, one of the walls has fallen down, spilling a huge amount of dirt and stone into the room.  The third time the party enters the room, it has collapsed and become impassible.

4. Room-Specific Random Encounters.  We already have random encounters specific to each floor (usually tied to a specific enemy level) but that's partially by convention more than anything.  There's nothing stopping you from having a random encounter table be specific to a room, instead of a floor.

In the Library, modify the random encounter table as follows: 1 - 2d6 goblins have been ordered to "get smart" and are here eating books unhappily, 2 - 2d6 skeleton servitors of the complex, returning some blood stained tomes recovered from a rival adventuring party, 3 - 1 mechanical librarian (stats as iron golem) who makes a reaction roll based heavily on how loud the adventuring party is being.  It will also scan them for stolen books.  The other 3 random encounters are unchanged.

Introducing Elements of Randomization

Unsurprisingly, random encounters do a really good job of randomizing the dungeoncrawling experience.  I love being surprised when I DM, and random encounters are part of that.

I don't really have any good alternatives to random encounters here.  Random encounters are great.  Instead I'll just offer some pointers to using them effectively.

1. Make sure you're using reaction rolls.  It's always interesting when you roll a very positive reaction for a monstrous enemy, or a very negative reaction for a normally friendly NPC.

2. Make sure that your list of random encounters is universally applicable to the area that you've linked to it.  DMs will ignore a random result if it makes no sense (as they should).  For example, if the DM rolls "hill giant" while the players are in a small hallway, the DM will ignore that result and probably hand-pick a different one.  This is a loss, because now we're losing one of the primary benefits of the random encounter list.

Try to populate your random encounter lists with things that are appropriate to the area.  Break up your dungeon level into sublevels if needed.

3. Link your random encounters to the dungeon.  I've said this a few times already, but "2d6 goblins" is not as good as "2d6 goblins from room 19" or "owlbear fleeing from 2d6 goblins" or "1d4+1 knights here to steal from the goblins in room 19".

4. Make your encounters impactful.  You want a random encounter to affect more than just that one encounter.  You want it to affect the whole dungeoncrawl.  Include something that makes the dungeon easier or harder.  Introduce a complexity.

"2d6 goblins + the goblin king" is great because now the players can capture the goblin king and ransom him back.  Or just kill him.

"The mummy pope from room 31.  If the mummy pope dies, the dungeon starts to collapse.  (This was told to the players before they entered the dungeon.)" Good--this has repercussions beyond the current encounter.

"5d6 nervous goblins demand that you guide them back to the Goblin Hole on Level 1".  This is great because now there's a very clear direction the encounter can take.  I sometimes write random encounters like this--where it's already a little pre-scripted--and then don't bother making a reaction roll.  Yes, you lose out on the random element that might surprise you, but you get something that may be more interesting that what you can come up with on the spot.

Relinquished card art from Yu-Gi-Oh

Spirits of the Underworld

If you've played roguelikes at all, you're aware that sometimes the game just dumps a new condition on top of you.  Sometimes these are helpful, more often they're painful.  

Spirits of the Underworld are powerful creatures that don't attack the party directly.  They just hang out, following you around and inflicting some effect.  Add them to your random encounter table.

The party can (1) ignore them until the spirit gets bored and leaves, (2) run away (using the typical fleeing rules), or (3) attempt to kill the spirit (although most of them are pretty powerful).  

Dead spirits will return to life after 19 days unless somehow prevented.

Generic Stats: HD 8, chain, attack 1d6/1d6/1d6, can turn ethereal

Ape of Progress

A tutelary spirit of the Underworld.  Just a giant gorilla head (8' tall) with muscular arms and legs sticking out.  Red skin, shaggy grey fur.  Wants you to succeed and be brave, but would rather see you die a hero than retreat as a coward.

Shows up behind you and prevents you from going backwards.  Will eventually get bored after 1d4+4 hours and fall asleep.  Alternatively, if you feed it a delicious meal (rations don't count), it will give you one of its fingers (can be used once as a scroll of passwall) and leave.

Combat Ability: if it hits you with two attacks on the same round, it grabs you with both arms and throws you into a random room in the dungeon.

The Deathbird

A tutelary spirit of the Underworld.  Lurches into the room like a gleeful mortician.  Tall, skeletal bird thing with three wings and a bird skull head.  Wants you to understand loss and death in order that you can appreciate life more.  All damage (dealt and received) is doubled in its presence.  

It will leave after an ally (PC or hireling) dies.  Once that happens, it will help you conduct a respectful funeral (although it will expect you to shed tears and talk about what you've learned from this death).  Alternatively, it'll get bored after 1d4+4 hours and wander away.  

Alternatively, you can appease it by offering it grave goods worth at least (1d6+3)*100 sp.  If you offer it an especially great sacrifice (10x higher than required) it will grant you the ability to speak with dead 1/day.

Combat Ability: On the first round of combat, it summons the death wind.  All living creatures in 50' must save or drop to 1 HP.

The Ineffable Quong

An albino giraffe with a head on both ends, except it has not heads--the necks just taper into singular horns.  On eye side of the body is a glassy black eye.  The Ineffable Quong blocks all magic in its presence.  Spellcasting, scrolls, potions, etc.

It demands a sacrifice of magic items and eyeballs.  You'll know when you've sacrificed enough--a tongue will slide down and pluck all of the objects into a ventral mouth.  If you give it an especially good offering (e.g. a magic artifact and 100 eyeballs) it will give you one of its heads to use as a staff (lets you use any scroll twice).

Combat Ability: On a hit, you must save or a random magic item in your possession explodes, dealing Xd6 damage to you, where X is the approximate level of the spell effect that it contained.

The Great Spirit of Darkness

A malevolent spirit of the Underworld.  It wants to see you all dead or corrupted.  Light shuns the touch of this spirit; it's true shape is impossible to discern.  However, it is tall humanoid with a large head, covered in shaggy fur, with enormous wings that wrap its body.

While the Great Spirit of Darkness stalks you, your torches shed half as much light and last half as long.  Additionally, all random encounters have a 1-in-6 chance of surprising you.

The Great Spirit of Darkness will get bored of you after 1d4+4 hours.  It cannot be appeased, but it can be tricked.  If the party splits up, it will not know who to follow.  It's very intelligent, but it is hampered by the fact that it doesn't understand exactly what humans are.  For example, if you put your clothes on logs and then throw the logs in the river, it may think that the logs are you, and follow them.  Other things that might work: faking your own death, burying yourself in mud, etc.

If you do something really fucked up to win its approval (e.g. sacrifice one of your friends) you will win it's blessing, but you'll really wish you didn't.  You'll gain darkvision, cannot leave the Underworld, and after the adventure is complete, you'll wander off into the darkness and become and NPC.

Combat Ability: At the start of combat, casts blindness on all creatures within 50'


  1. The Ape of Progress would be a really great name for a DEVO album.


  2. This is a fantastic analysis of random encounters in dungeoncrawling! I appreciate the depth of thought you've put into examining both the traditional uses and innovative approaches to enhance the experience. The time pressure ideas are especially creative, offering fresh ways to maintain tension and urgency. The Spirits of the Underworld section adds an intriguing layer of challenge and narrative potential to any game.


  3. Great concept. I am looking forward to using it.