Tuesday, September 29, 2026

World's Largest Rewrite: Invisible Fire, Cube that Gets You High, IRL Bears

#19: Cave Locust. This is another of old-school D&D’s weird bugs, and another example of a superficially ordinary monster that has a lot going on. Cave locusts have five special features: stone camouflage, a random encounter-inducing shriek, a jump that can turn into an accidental attack, debilitating spit, and poison immunity. This makes it a surprisingly dynamic creature, where a lot of the outputs of encountering it are distinct from the conventional combat encounter.

They have poison immunity because they eat fungus, so we can put them in the vicinity of our previously established fungal creatures. They might be natural predators of the Mother Fungus, and thus implicit rivals of the gecko kobolds and other creatures who seek to exploit or symbiotically ally with the Mother Fungus. 

#52: Griffon. Like the hippogriff and the pegasus, the griffon is a member of the amply populated “flying animal mashup” category. Their urge to attack horses is their main distinguishing feature. 

…It doesn’t say they only attack mundane, land-bound horses, so perhaps they are predators to the hippogriffs and pegasi as well. At 7 HD, they are much bigger than either of those creature types, so they’re plausible as apex predators. Maybe shared fear of the griffon is the only thing keeping those rivals from attempting to drive the other out of the area. 

The Overhaul gives us a nice body variation table, similar to what we used for the chimera. We get lizard body (armor as plate) and peacock wings (half-speed flight). The peacock wings make it a slow and ungainly flyer, so it has to rely on ambush tactics to catch its swifter prey. Imagine an armored peacock the size of a garbage truck screaming in out of nowhere to try to eat you. I would be terrified too, and I’m not even a horse.

#120: Trader. Do you like duplicative stat blocks for barely distinguishable groups of humans? Because the OSE bestiary has duplicative stat blocks for barely distinguishable groups of humans. Our traders are only thinly sketched here, but appear to be lower on the tech tree than the merchants we met before (they trade in "carved wooden items, furs, spices").  

But they do have mules, which are canonically important to our dungeon! So I’m giving these guys a pass. We’ll put them inside the dungeon, to add some contrast with the merchants on the outside; they might have some useful supplies to offer adventurers. 

#20: Centaur. Uhh… how far do we want to take this griffons-eat-horses thing? I can’t think of any reason why the griffon would turn its nose up at a creature that is mostly horse… although with bows, the centaurs are at least better equipped to drive the griffon off. The Overhaul plays up the centaurs’ wild, rebellious side (“we bribed them to attack our enemies, but they spent our money on wine”). They’re prisoners trying to escape, but the griffon’s presence is making it hard for them to make a clean break for it.

#54: Harpy. Another classic monster, and the stat block is what you expect, although they have magic resistance with a +2 save, a feature they seem to have lost through the editions (the 2014 MM omits it). The Overhaul is similar, but does note that they are “divine servants of vengeance.” This harkens back to their origin in Greek myth, where they were usually acting to enact divine punishment, not just to serving as generic monsters. Like the wights and gargoyles, this is another opportunity to turn a conventionally evil monster, which would make sense as a prisoner, into part of the warden staff for the prison. Absent direct oversight from the prison builders, the harpies are experimenting with how shitty they can be without attracting celestial punishment. 


An animated gif of a gelatinous cube, quivering vertically, with a skull and other objects embedded within it.


#56: Hellhound. OSE statblocks alternate between “yeah, what I expected” and “hold on, there’s some unexpected details here.” The hellhound is in the later category. They are “cunning, and very intelligent” but presumably not sapient, as other creatures keep them as pets. They have a variable HD range for some reason; it gives them more HP and more accurate attacks, but doesn’t change damage or anything else, so I’m not sure what purpose that serves. They can detect invisible things quite well, presumably reflecting their canine sense of smell and hearing, or their ability in myth (e.g., Japanese) to see through tricks.

The Overhaul variants are interesting. I rolled “Glass Hound. Invisible. Fire is also invisible.” So they’re trapped in the prison, they’ve broken containment, and they have started setting fires that burn like normal, but are invisible. Fire that you can smell and inhale, but not see, is a terrifying idea. How do you know you have actually put it out? This is not just a monster encounter, but an entire dungeon hazard for the PCs. Excellent. 

The invisible fire is such a huge problem that it explains why there's a river flowing through this prison. It wasn't an accident; it was deliberately diverted here to douse the invisible fires. 

#42: Gelatinous Cube. Deservedly one of the most famous and celebrated D&D monsters. This stat block is as expected. Like the basilisk, we could imagine the cube as a contained threat that was let loose in an attempt to stop other monsters from escaping. Like the blink dog, it can easily bypass bars and portcullises. It can devour other would-be escapees while making no effort of its own to escape. 

The Overhaul gives them a “wet wrinkly steak” texture and “gets you really high if you lick it.” So weaker dungeon denizens are being paralyzed and then eaten/and or intoxicated by the cube. Some factions have even captured smaller ones to intentionally take advantage of the intoxicating effect. I was gonna escape from prison, until I got high.

#71: Manticore. Like the griffon and so many others before it, this is another airborne mythological combo meal. The manticore’s ability to snipe from long range sets it apart from those other creatures, but it also has a finite amount of ammunition, so it needs to choose its targets carefully. The Overhaul adds some good lore, including that manticores propagating as evil dreams when they die, which would give the prison builders a good reason for capturing them, rather than killing them outright. This manticore is prowling an area of halls with doors too small for it to exit, using crudely made arrow slits to snipe and poison passerby. It cares more for these pointless acts of cruelty than it does for actions that might bring about its own freedom.

#7: Bear. Just use bears! You can do the entire WLD gimmick in no time at all. Just use bears! Who will notice? I would notice. I would know. I would be disappointed with you. I would be disappointed in myself. I’m too deep into this exercise to JUB my way out of it now.

Anyway, OSE includes four types of bears, and they map to their real-world counterparts pretty well in terms of size and combat danger. No sun bear stats, sadly.

One feature of the Overhaul that I enjoy is how it treats mundane animals. The 5E.2014 MM packs all the normal beasts into short bits at the back of the book, and I get it; you don’t need a lore block explaining what a deer is. But if they’re worth so little attention… why include them at all? The Overhaul, in contrast, is first and foremost a book for inspiring interesting encounters, rather than a book for referencing stats, and it has three tables of evocative bear variations. You could probably run several dozen bear encounters using the Overhaul with getting bored. I think you would be lucky to get one good bear encounter out of the 2014 manual.

To come full circle and return to our very first post in this series, our bears are here to GET THAT SWEET KILLER BEE HONEY. They’re probably immune or at least highly resistant to the stings. They’re “belligerent, secretive.” They’ve created a den within the prison that includes a “mummified carcass of an enormous bear.” They’re great! Just use bears!

#49: Gorgon. This is the Gygaxian gorgon, the metal bull that breathes petrifying gas. If you're really cool and smart like me, you know that this type of "gorgon" is actually a petroblepas. If we want to quadruple down on the stone theme, these creatures would be released for serious riot control situations, petrifying entire crowds of prisoners.




Tuesday, September 22, 2026

World's Largest Rewrite: Mickity Thumpduck and His Gang of Halflings are Horrible and They Aren't Even Prisoners Here

#61: Hydra. The hydra absolutely makes sense as a prisoner. It is interesting that the OSE hydra lacks the ability to regrow severed heads, which is core to modern D&D’s hydra. Rolling on the variant table in the Overhaul gets “centipede hydra.” Ew. But it immediately made me think of the cellipedes we introduced earlier. The cellipede hydra is the broodmother of all cellipedes, and each time a head is severed, a new one will grow, sprouting a brand-new key, which fits into a lock somewhere in the prison. The cellipede hydra becomes a sort of dynamic solution to barriers that the PCs can "harvest" keys from, but may not want to kill, to avoid missing out on future keys. 

#53: Halfling. Like our recent hits on dwarves and elves, halflings have basic OSE entries and no dedicated Overhaul entry. As with those previous cases, we can use the Overhaul’s adventurer section to get a feel for the local halflings. 

  • Vice: Envy
  • Goal: Drugs and retirement
  • Why are they here: Utterly lost
  • Subtype: Brawling
  • Leader: Mickity Thumpduck; small eyes, leather cap; profession: justice; hidden miniature crossbow 
  • From: Gamwich village, in the Stenrind region

I’ve praised the Overhaul a lot during this series, but I can’t stress enough how well-calibrated the tables are to produce gameable output. I could run Mickity Thumpduck and his idiot gang of corrupt rent-a-cops right now, no further prep needed. They heard about the dwarven treasure, showed up hoping to get a cut, and are now lost inside the prison.

#57: Herd Animal. Stampede is the interesting mechanical hook here. The Overhaul (understandably) does not not have entries for mundane moose and oxen, but it does have one for telluric goats. These are mineral-eating goats, so pose a bit of a rust monster-esque challenge for adventurers. Rolling on the tables in the entry, we get bite effect of “target’s head and body must face north” and a reason to fight them as “whenever telluric goats appear, landslides and earthquakes are sure to follow.” This suggests a possible reason for the insecurity of this previous secure underground prison. The goats began (or exacerbated) the decline of the prison, and now roam its halls, seeking delicious ore. 

#75: Merchant. Yeah, this is a separate entry from Normal Humans. The stat block itself is not important. The entry instead sketches out the size and composition of a merchant caravan, so we’ll follow the same logic and place these merchants outside the dungeon. They’re probably keeping their distance from the brigands, hoping to buy weird stuff that adventurers extract from the prison.

These caravans are big. I rolled 1d20 for number appearing and got 10 merchants. That means we have: 

  • 10 mounts (one per merchant, implicitly?)
  • 20 wagons (2 per merchant) with corresponding beasts of burden
  • 40 L1 fighter guards (4 per merchant)
  • 2 L2-3 fighter lieutenants (1 per 5 merchants)
  • 1 5L fighter captain 
  • 2 extra animals 

These guys are a serious force! For exterior factions, the brigands might be stronger, if there are enough of them to form a fortified camp and score a genuinely high-level leader (we didn’t nail down William Osprey’s level in the brigand entry). But even if the brigands are stronger, the merchants could put up enough of a fight to make them think twice about throwing down. So it is an uneasy detente outside the dungeon.

#114: Squid, Giant. As we foreshadowed in the giant octopus entry, OSE delivers too much tentacle-based trauma for one game to sustain. These cephalopods are broadly similar, with the giant squid differentiated the most by some boat-attack-focused abilities. As we did with giant octopus, we’ll again use the Overhaul’s kraken table for inspiration, and we get “vampiric.” This is a bit of a play on the real-life vampire squid, or Vampyroteuthis infernalis (vampire squid from hell) if you’re nasty. Wikipedia articles are an excellent source of monster content, and there’s no reason we can’t raid this one. Look at the spikes on that hood. Imagine this guy dropping on an adventurer’s head and draining their blood, while using strobing bioluminescent light to confuse and stun would-be rescuers. We can even be really literal and associate these guys with the vampire we already placed in the dungeon.


An animated gif of a vampire squid unfolding and inverting itself to show its teeth-like profusions in a defensive or threatening manner


#110: Snake. Speak of the (vampire) devil, the next randomly chosen entry is for the snake. We already decided we wanted a giant albino snake to keep the vampire company, which brings Lair of the White Worm to mind. Snakes are nasty in OSE. We can size up the giant constrictor, and maybe give it a vampiric bite as well, depending on how we want to embellish the relationship between the vampire and the snake.

#136: Wyvern. From snakes to their heraldic descendants, wyverns. Like the snake, the wyvern has save-or-die poison. The Overhaul, interestingly, doesn’t treat the poison sting as a default feature. Rolling on the variant table, we get “Gulper: Neck sack, wattle, one nostril.” Imprisoned for its ravenously hungry behavior. 

#90: Pegasus. This far into this series, we have a lot less blue sky design, a lot more filling in spaces between already established monsters and factions. Pegasi are potential flying mounts for the jailers; the fighter jets to the bomber that is the roc we found earlier. They serve lawful characters. Perhaps the pegasi are no longer willing to aid the dwarves, sensing that some of them are compromised? 

#87: Ogre. They hate neanderthals. Otherwise, they’re bog-standard ogres. But the Overhaul can give us a tailored ogre.

  • Name: Durl
  • Feature: Thick forehead ridge
  • Weapon: Hook and chain
  • Crime: Despoiled sanctified ground
  • Type: Fumeguts, leaks black fumes, twice per day, opaque fog, 30’ radius, 10 rounds
Locked up for farting in church. Sometimes these entries write themselves.

#102: Salamander. Ya got your hot lizards and your cold lizards. They are mostly similar, although flame salamanders are neutral, and frost types are chaotic. We'll choose the frost type as more fitting prisoners. The Overhaul directs to elemental spirit (where our gnome came from) and suggests barbegazi, which is more evocative than "salamander." These guys are "despised yet treasured local rivals" who look like "old, dark-eyed, serious men and women." That fits with a sort of frost witch folklore.




Tuesday, September 15, 2026

How to Set Stakes, or When Binary Resolution is About More Than Two Choices

This is a good post by Behind the Helm. Maybe even good enough to go in the hall of fame.

It has the simple, elegant "rule of threes" vibe of this post, which outlines a principle so good that I have it attached to the computer I use for running games.

What both of these posts are getting at is that adjudicating uncertain or dangerous situations in an RPG requires the GM to think critically about possible outcomes, and what outcomes the dice should be suggesting.

Many RPGs fail to teach GMs that game action is viewed through the lens of the ruleset. Rules clarify  and focus the game action rather than define it. Calling for a roll of the dice is not (just) a chance for excitement and risk; it is a way to orient everyone at the table around what is happening. A roll of the dice syncs everyone at the table with the current fiction.

Yes, part of this is just knowing when not to roll the dice. It just succeeds. But if dice must be rolled, the GM must understand how to set stakes. 


An animated pixel art image, depicting an airlock on a space station, with flickering lights


I have just begun running Mothership, and its an interesting game to examine in the context of Behind the Helm's post. At a casual glance, it feels like a binary resolution game. Roll under, succeed; roll over, fail. Doubles are crits. My D&D-trained brain says, binary resolution plus crits. Easy, right?

But how closely did I read the Warden’s Manual? On page 20, regarding the marine class: “Interpret their failed Combat rolls more generously than others.” Hmmm. Page 26-27 includes a lovely adjudication flowchart; the "warden sets the stakes" phase of the chart is clearly an opportunity to choose binary resolution between success/success-at-cost/failure, although it doesn’t explicitly say that. Page 30, under “there’s more than success and failure at stake,” is essentially making the same point as Behind the Helm's post. 

But I missed it! I read the manual cover to cover before I started running the game, and I didn’t really internalize what those bits collectively mean until I reread it with this blog post in mind.

In one player’s very first session in our Mothership game, they rolled exactly the target number. We had to look it up and confirm that only results under the target succeed, so it was a failure. But I had already set the stakes for the roll at total success or success-at-cost, so I already knew how to adjudicate it. 

The character escaped from their pursuer, but wasn't able to fully close the airlock door. Their pursuer was still trying to pry it open. Binary resolution supported by thoughtful stakes-setting framed the action and made it easy to say to the players, “well, what do you want to do next?”

Tuesday, September 8, 2026

You Can Not Have Magical PCs if Strict Time Records Are Not Kept

The Druid

The druid draws power from ceremonial attunement with the seasons. They can cast spells of endurance during the winter, renewal in the spring, growth in the summer, and harrowing in the fall. Their power is amplified during solstices and equinoxes.

The Witch

The witch draws power from the cycle of the moon. Their power waxes as the moon does. Spells of obfuscation and trickery with the new moon give way to spells of dominion and transformation with the full moon.


An old book illustration from "Witchcraft and Superstitious Record in the South-Western District of Scotland," depicting a series of witches ascending into the night sky on brooms, with a full moon at the center of the image


The Hierophant

The hierophant draws power from the sun’s position in the sky. Their magic is strongest at high noon, and weakest in the middle of the night. They wield great power during lunar eclipses and blood moons.

The Mythologist

The mythologist draws power from the shared cultural institutions that subtly inform quotidian life. The days of the week and the names of the months are not arbitrary; they speak to ancient traditions and powers. Those who remember the meaning behind the names can call on the power behind those ancient stories.

The Liturgist 

The liturgist draws their power from the days of the saints. They may invoke the power of a particular saint, but only on that saint’s day. Some saints have broad but diffuse remits; others have narrow but potent ones.

Tuesday, September 1, 2026

World's Largest Rewrite: Noble Neanderthals, Grimy Goblins, Execrable Elves

#80: Neanderthal (Caveman). Here we find more of the lost world vibe that is pretty strong in early D&D, but mostly gone from the modern game. The neanderthals are a bit more interesting than some of the other bestiary entries that can be boiled down to “Normal Human with slightly different equipment, group composition, and treasure.”

  • Friendly with dwarves and gnomes. Turn that mancave into a demihumancave. 
  • Lawful. Thog part of community. Thog honor social contract.
  • Two 6HD leaders (one male, one female) live in the neanderthal lair. They are 10’ tall and of "a related but distinct race." I presume this comes from pulp fiction like Robert E. Howard’s stories and Shaver Mystery stuff; tales of speculative anthropology, crypto-history, devolution, and civilizational decline, suggesting that primitive humans might live under the sway of an older and more powerful species.
  • Attack ogres on sight. Hate goblins and kobolds. They learned it from watching the dwarves?
  • Sometimes keep white apes as pets. Who saved who?

Within our prison dungeon milieu, the neanderthals obviously make sense as members of the lost world “section” of the prison. But their alliance with dwarves and gnomes gives us another hook to work with. Let’s say that as the dwarves and their gnomish allies began to lose control of the prison, they thawed out the neanderthals and deputized them as prison security guards. The neanderthals and the dwarves are now separated by dangerous parts of the dungeon, with the dwarves toward the "south" and the neanderthals in the "north," where the lost world stuff is. 

#108: Shrieker. Of course prison builders in a D&D world would use shriekers as “alarms” to detect escapees. It is interesting that OSE shriekers can move, but very slowly. Shriekers in 5E are stationary (lazy). We can presume the shriekers have drifted somewhat from their original “stations.”

The Overhaul doesn’t have a shrieker entry, but we can revert back to the richly populated myconid entry we used for the Mother Fungus. On the hallucinogenic mushroom effects table, we get “Walls move and churn. Navigation difficult.” It would make sense that in addition to screaming, the shriekers would emit spores that would befuddle would-be escapees. This can also help explain why some prisoners haven’t yet escaped the prison; they're watching the walls melt.

#47: Goblin. The one detail from OSE that surprised me is that the king and bodyguards don’t suffer the sunlight penalty that affects ordinary goblins. Otherwise, these are your bog-standard gobbos. The Overhaul gives us five (!) pages on goblins, making them one of the most richly detailed monsters in the entire book. The Overhaul takes some liberties with the stat block, giving them 0 (!) HD (2 HP) and a morale of 4 (!), presumably to differentiate them more from other humanoid-style creatures that 1st-level PCs might encounter. Rolling on a few of the tables gives us some details:

  • Special ability: Gravelmouth. Can digest anything.
  • What are they doing: Malicious destruction.
  • Leader: Bluck-ing Ding Tark. Necklace of teeth.
  • Elite weapon: Boiling oil cauldron.
  • Superweapon: Doomwand.
  • Mounts: Larval worm. Hmm… maybe they’ve tamed some Caecilia?
  • Loot: Turnips.
  • Bullying target: Kobolds.
  • Where goblins come from: “If you use a turnip as a ‘marital aid’ and plant it in a dunghill it grows into a Goblin." Skerples, why…
  • Fear and response: Music; paralyzed
  • Leadership method: Elective democracy
An embarrassment of riches. Democracy makes them our most commendable prisoners, although I don't like what they have been doing with it. Never eating a turnip again.

#77: Minotaur. The OSE minotaur is pretty basic. Dwells in mazes, charges like a bull. The Overhaul can beef it up (I’m sorry). 

  • Why must this minotaur die? Technically the heir to the dying ruler’s throne. 
  • Name: Harnthgar
  • Feature: One blind eye
  • Weapon: The Big Club

So our minotaur is a VIP (very important prisoner) who was put here because he is the heir to a powerful kingdom. Too important to kill, to dangerous/embarrassing to keep at court. One of god's own prototypes. Now there's some kind of succession crisis and the kingdom needs him, but there’s no easy way to retrieve him, due to the prison’s decline. Perhaps one or more of the organized factions on the outside, trying to get in, are seeking the minotaur?

#38: Elf. Elves don’t have a dedicated Overhaul entry, but we can once again use the Adventurer section to develop ideas. The tables there are intended for rival NPC adventuring parties, but mostly work just as well for a faction. These elves have…

  • Vice: Distressing greed
  • Goal: Bloodshed
  • Why are they here: Found a map
  • Subtype: High elves
  • Leader: Vaeleth Duskstrider; unwrinkled, charming face; soldier; lifedrinking longsword
  • From: Kethampton 

Oh, wonderful, I already hate these guys. Bloodthirsty, greedy elves in search of treasure. They are probably very well-mannered and good at putting up appearances, but are really just sadistically cruel shitheads.


A 1933 sketch by Pablo Picasso depicting a minotaur in the foreground, dying or in pain. Faces in the background look on; one person reaches out to caress or comfort the minotaur.


#130: Water Termite. Ah, yes, the classic D&D monsters. Goblin, minotaur, elf… water termite. Again I am charmed by some of the OSE oddities that don’t appear in modern editions.

Like the beetles and rats, the mechanics of the water termite imply An Entire Situation. They are pests that consume wood, including the undersides of ships and boats, with a built-in chance of someone noticing their presence. They might have been drawn to the dungeon as the sea seeped into the lower levels, coming into contact with wood... delicious wood. They are probably also living inside the sperm whale’s stomach, feeding on the crashed ships therein. 

#76: Merman. Nothing surprising here. Let's go to the Overhaul.

  • Leader: Tenchal 
  • Feature: Sensory barbel-whiskers
  • Lower half: Eel
  • Trades/treasures: Untraceable poison
  • Want: Return of a kidnapped merfolk

Once again the Overhaul’s random tables provide a connection that would not have otherwise occurred  to us. The merfolk are willing to trade an “untraceable poison,” probably derived from some deep-sea creature. Sounds like just the sort of thing our dwarven leader would have used, right? They’ve traded that poison for the freedom of a merfolk leader (Tenchal) trapped in the prison. The dwarves have to return this prisoner now, but that process is probably complicated by the distressed state of the prison. The merfolk are getting impatient…

#28: Djinni (Lesser). Like the sea serpent before it, we have a lesser creature with no greater equivalent. Maybe this is some inherited B/X design, where the “greater” creature is assumed to be something lower-powered PCs would never encounter.

Regardless, amid other, flashier powers, the djinni has two powers that are particularly interesting to our prison builders. They can use each of these three times per day.

  • Illusion: Visual and audial. No concentration required. Remains until touched or dispelled.
  • Conjure soft goods / wooden objects: Up to 1,000 coins weight. Permanent.

So a djinni is summoned and bound to serve the wardens. They have it spend its daily uses conjuring wooden objects – all the non-stone components of the dungeon, like the doors. This compliments the cockatrice/basilisk/medusa/gorgon system of stoneworking. The djinni uses their illusion powers to create illusions that will complicate escape from the prison. Many of these illusions have been dispelled overtime by touch, but some remain. Whether through accident or betrayal, the djinni, like the medusa, is now trapped in the prison it helped build.

#58: Hippogriff. The most interesting thing about the hippogriff is that they hate pegasi and will attack them on sight; I guess because the pegasi are competing for similar “flying amalgamation from mythology” category that the hippogriffs live in. We haven’t even reached the griffons yet.

Pegasi make sense as mounts for Team Lawful, so we’ll assume these hippogriffs are mounts for the twisted elves we just met. The elves are able to enter the dungeon from a non-obvious angle because they have flying mounts.

#50: Grey Ooze. These are the rock-camouflaged, armor-dissolving oozes. While I didn’t want all of our slimes to be associated with our black dragon, the grey ooze is the one that fits the best with their acid vibe. The black dragon can loogie these out and send them roaming places where it cannot go, but they're too dumb to do complex tasks, which might mean the dragon would be willing to parley with adventurers. 

Tuesday, August 25, 2026

World's Largest Rewrite: Rats are Terrifying, I Want to Leave This Dungeon Right Now

 #25: Crocodile. We got giant crocs, we got large crocs, we got normal crocs. In contrast to OSE sharks and 5E crocodiles, there is no unique mechanic, like a bite-and-grapple; they just get bigger and bite harder. We’ll go with the giant crocodile, as it has a bit of lore – “usually encountered in Lost World regions” – that fits with our idea that the prison has a zoo of ancient pseudo-extinct beasties.

#95: Rat. Rats are typically either a tutorial challenge for newbie adventurers, or little more than set dressing. I like that OSE treats rats rather seriously. They have five (!) special characteristics, making them much more mechanically distinct than a lot of OSE’s other animal monsters. 

  • Afraid of fire. Will flee unless “forced to fight by summoner.” Their fear of fire means they are a puzzle monster; like the beetle swarm that invites the PCs to escape by diving into water, the rat swarm has built-in counterplay. We’ll decide later if these rats are compelled by a rodent-summoner, or just out there swarming on their own volition.
  • Disease. There’s a 1-in-20 chance of disease, which allows a save, and the disease has a 1-in-4 chance to be deadly over 1d6 days. Given that the disease has no immediate effect, I would probably keep a rat bite tally during any encounter with rats, and sum the infection odds to a single roll after the encounter is over. The disease system here is pretty forgiving, but obviously scales in danger with the number of rats encountered…
  • Pack. The equivalent of swarm rules from modern D&D. It does not specifically state how the pack feature interacts with the disease odds; I would rule that swarms have a 5-in-20 chance of inflicting disease, versus a sole rat’s 1-in-20.
  • Attacking in water. Excellent swimmers, no penalty. Swarms of disease-ridden rats chomping away at a swimming adventurer is scary enough on its own, without even considering…
  • Engulf. The PC saves versus death or falls prone, unable to attack until they can stand again. This is pretty scary in a land encounter. In the water… well, when your PC sinks beneath the surface, covered in ravenous, diseased rodents, no one is going to mistake that for a training wheels encounter. 

#101: Rust Monster. Another classic creature that is brutal in its old-school presentation. Magical items only have a 10% chance per “plus” to resist the effect (the entry does not say if metallic magical items without pluses even get this chance). Oof.

I like the rust monster as an invasive species, possibly drawn by the abundance of unprotected metal in the prison. Like the cellipedes, they are a kind of dungeon vermin that specifically plagues prison wardens. As much as adventurers hate rust monsters, prisoners love them, as they can quickly destroy metal cell bars, incidentally freeing the incarcerated.

So the rust monsters are hated and hunted by the guardian monsters, but beloved by the prisoners. Escaped prisoners are trying to capture and herd the creatures toward their allies, using the rusties to jailbreak those who could aid them in a more general escape from the structure.

#117: Thoul. We planned for this. Our thouls are bodyguards to the hobgoblin king! They were mutated with trollish blood, which caused runaway cellular replication; the ghoulish infection counterbalanced that explosion of life, and now these creatures live a tenuous existence, their trollish blood and their necrotic flesh caught in a delicate balance. 

#131: Weasel, Giant. Like the giant shrews before them, the giant weasels provide a surprising degree of mechanical crunch. They are tunnel dwellers who are good at tracking (favoring wounded prey) and have infravision. They attach to targets and suck blood (!), and treasure is found on the bodies of their victims, in their lair. This encounter writes itself. 

The giant weasels are invasive to the prison complex. They have burrowed down into the ground surrounding the prison, and created tunnels between otherwise unconnected areas. They show up 1-4 turns after a PC is injured, stalking the group, waiting until the PCs are in darkness, separated, or otherwise vulnerable. They then emerge from the nearest tunnel, attempting to grab a victim and drag them back toward their warren. If they succeed in pulling someone back into a tunnel, they move backwards, so that their victim’s body blocks pursuers’ line of sight. The weasel can continue to drain blood as they drag their victim to their doom. That’s a pretty intense encounter, for a superficially unimpressive creature.

But those tunnels also provide an opportunity to the PCs. Like our mother fungus, apes, and gargoyles, the weasel is not just a combat threat, but also a creature that creates an overlay on the dungeon, another network of connections that intersect and defy the built structure itself.


A simple animated "sticker" drawing of a happy-looking weasel, only a few frames long, cavorting or jumping


#55: Hawk. Not much to see here. We have normal hawk and giant hawk; they can swoop attack, and they are trainable. That’s it for OSE. The Monster Overhaul index directs us to another entry with a “why are they attacking” table, where we find “judgement-altering disease.” 

I’m going to combine that with OSE’s note that they can be trained, and use this as another opportunity to tell the story of the prison’s decline. The hawks were once kept by the prison wardens, perhaps used to track prisoners who escaped the walls and fled into the wilderness. They are now feral and have contracted some kind of illness that compels them to harry anyone who approaches the prison exterior, regardless of purpose. The brigands camped outside the prison have figured out some kind of combination of smells and colors that repel them, and have festooned their camp in associated materials (it makes them look ridiculous). 

#86: Octopus, Giant. We’re running into some overlaps as we get deeper into the OSE bestiary. The giant octopus lives in the same mechanical space as the lesser sea serpent, and we haven’t even gotten to OSE’s giant squid. The Overhaul’s index refers both to the kraken entry. Rolling there are on the variant table we get chameleonic; pulsing chromatophores. I’m reminded most strongly of the intelligent octopi in the science fiction novel Children of Ruin, who use colors to communicate in a way that the humans in the story don't understand at first. Making our giant octopi intelligent rather than yet another big sea beast could carve out some interesting space. Deeply curious creatures, they’ve been to drawn to explore the dungeon. 

#122: Triceratops. The OSE triceratops is an aggressive herbivore that charges on sight, presumptively behaving like a territorial bull. The Overhaul refers us to the same “herd lizard” category that we used for stegosaurus. Lets do something different and say that our knight Sir Guy Truthspeaker has captured a young triceratops and is using it as a mount. The other triceratops are agitated by the missing member of their herd.

#46: Gnome. The best bit in the OSE entry is “May make foolish decisions to obtain precious items.” They get along well with the dungeon's dwarves, so they fit neatly with an already-established faction. Like any good faction, some of these gnomes are on board with this whole “strip the magical prison of valuables” approach, while others recognize that this is a bad idea. The Overhaul gives us some unexpected material to work with, directing gnome-seekers to the elemental spirit category, where they are the earth/stone equivalents of nereids, sylphs, and salamanders. Rolling on the “local reputation” table, we get “the honored dead, reborn.” So the dwarves have summoned gnomes that they believe (rightly or wrongly) are reincarnated ancestors. That certainly adds an edge to the dwarves' betrayal.

#103: Scorpion, Giant. A good straightforward monster. Most OSE animals, even giant ones, are neutral, a pattern that holds true in modern D&D as well. But the giant scorpion is chaotic. I’m not sure why. It’s not because of the poison (the giant spider is also neutral). The chaotic alignment pushes me toward the idea that the scorpion was a prisoner (or specimen) in the dungeon, rather than an incidental invader. 

Tuesday, August 18, 2026

Fantasy Language Review: Infernal Institutions, Primordial Dialects, Sylvan Secrets, and Solving the Origins of Undercommon

 A year and a half later, we finally finish this series of posts! 

Previously:

Infernal 

Variations: Tyrannous taxonomy. Devils are obsessed with domination. But it is a relative, not absolute, power structure. Each devil spends their time obsessing over the creatures they can control… while also obsessing over the creatures that can control them Infernal is consequently a language dominated by social deixis. Speaking in infernal is a process of constantly reinforcing and emphasizing these terms; words of submission and supplication when addressing a more powerful creature; a completely different set of words of coercion and control when addressing a less powerful one.

An alternative approach: Burning words. Infernal is so infused with devilish energy that the very words they speak burn the tongue. For a tiefling, infernal fluency and fire resistance are complementary features. A creature from a cold-weather environment, or the elemental plane of water, might require protective mouth-gear or equivalent magic simply to speak such a language without harming themself.

Get weirder: Legalese. The Switchwander Courts in the Third Circle of Hell endlessly litigate anything and everything in existence. Whether language or legal procedure came first is a real chicken-or-egg type of question. Speaking Infernal anywhere in the Third Circle can create a binding magical contract, similar in effect to a Geas, with the severity and intensity of said contract proportional to the disparity in power between the speaker and the listener(s).

Primordial 

Variations: Forged from the four elements. It’s Dwarvish script again you guys! If someone is speaking Primordial – literally, etymologically, suggesting it came before other languages – why are they writing it in Dwarvish? Echoing our lore from the giant language post, we can posit that the Primordial language was spoken, but not written, until the dwarves lent it a script. Perhaps it was the combination of the four elements in their forges; metal mined from the earth, fire to shape it, air to drive the bellows, water to quench and harden it. The dwarves were the first to tame the four Platonic elements, and they encoded that mastery in writing. 

An alternative approach: Divisive dialects. The 2014 PHB notes that Auran, Aquan, Ignan, and Terran are dialects of Primordial, but that speakers of the dialects can understand each other… which is fine, but means that the dialects are just for flavor, and as written, don’t have any mechanical or roleplay heft. Complicate dialects by requiring an appropriate check when switching from one dialect to another. Failure risks mingling terms and syntaxes, inadvertently slipping into a quasi- or para-elemental patois, which any speaker of the four “true” dialects will consider an insulting debasement of their pure lingual tradition. Skilled translators who can avoid mistakes like this are in high demand.

Get weirder: Tension in the tenses. Perhaps the four elements should not be thought of as dialects but rather different tenses within the primordial language. A speaker of Primordial might use the rigid and unchanging Terran in the past tense, blazing Ignan words in the present, and abstracted air for the future tense. Flowing water fills the gaps and takes any of the modal constructions that don’t fit the past/present/future structure.


A 16th-century French woodcut depicting a strange creature with one eye and long, floppy ears; it holds a wooden tool, possibly a flute, close to its mouth

Sexy fey singles in your area!


Sylvan 

Variations: Elvish antecedents. As we mentioned way back when we covered Elvish, Elvish and Sylvan may be related languages. Sylvan creatures understand that Elves speak a related language, but because they are prideful and mischievous about the etymological linkage. On any interaction with the fey, the fey will inevitably find a way to critique the Elven language in their response, noting all the ways that Elvish allegedly debases Sylvan. 

Alternative approach: Witching words. Many fey have magical charm abilities, and this magic sometimes seeps into their spoken words. Characters without some resistance to fey magics may find themselves in trouble if they ask for aid or try to influence Sylvan creatures. If a player fails a Charisma ability check, reaction roll, or similar mechanism while interacting with a fey creature, that creature may use any charm magics it possesses (Charm Person, Suggestion, etc.) immediately on that character, without any obvious indication that they are doing so (i.e., no somatic or verbal components required).

Get weirder: Rhymes and riddles. True to folklore, the mischievous spirit is so strong with these creatures that tricks and games infuse their very words. In any conversation where a non-fey creature asks a fey creature a question, the fey creature will think of a “riddle-type” answer to the question. If possible, this answer is something that is analogous in some way to the real answer (e.g., something that follows the logic of very basic riddles, like a play on a homonym). The fey creature in question will be happy to draw the conversation out, encouraging the inquirer to solve their stupid riddle, refusing to answer those who won't play along.

Undercommon 

Yeah, this one has issues. As with deep speech, let’s start with a census of the speakers. 

  • Beholder and variants (deep speech, Undercommon; the zombie beholder, like other zombies, understands Undercommon, but doesn’t speak it)
  • Cloaker (Deep Speech, Undercommon)
  • Yochlol (Abyssal, Elvish, Undercommon)
  • Drider (Elvish, Undercommon)
  • Duergar (Dwarvish, Undercommon)
  • Drow and variants (Elvish, Undercommon)
  • Flumph (understands Undercommon but can’t speak it, telepathy)
  • Fomorian (Giant, Undercommon)
  • Deep Gnome (Gnomish, Terran, Undercommon)
  • Grimlock (Undercommon)
  • Kuo-Toa (Undercommon)
  • Mimic (no languages, but “a rare few evolve greater cunning and the ability to carry on simple conversations in Common or Undercommon”)
  • Mindflayer (Deep Speech, Undercommon, telepathy)
  • Nothic (Undercommon)
  • Quaggoth (Undercommon)

This doesn’t make a lot of sense. Why do so many creatures speak Undercommon as their only language? 

We can start to sort this out by breaking these creatures down into a few groups. We’ll disregard the “rare” talking mimic. I don’t know why the Flumph needs to understand Undercommon when nonverbal telepathy is core to its concept, so we’ll throw that one out too.

Random aberrations (beholder, cloaker, nothic). As with our conversation on deep speech, I think beholders should have their own language. It is hard to know what to think of cloakers as they are essentially ambush clothes, and the game doesn’t tell us why they are smarter and wiser than the average person. A solitary creature like the nothic has no use for a trade language, so it should speak deep speech, or have some text to the effect of “speaks the languages it knew before its transformation.”

Drow and their associates (yochlol, drider, drow, quaggoth). These creatures are united by Elvish (assuming we treat them as elves at all). Undercommon uses Elvish script, which implies that the drow, as one of the major underdark factions, founded this trade language. 

Underground versions of familiar surface creatures (duergar, fomorian, deep gnome). Like the drow, these creatures can just speak an underdark dialect of their ancestry language.

Mindflayers and their associates (grimlock, kuo-toa, mindflayer). If we’re keeping deep speech, have the grimlocks and kuo-toa speak debased, simplified versions of that language.

So where does that take us? We have several overlapping options.

Strike Undercommon entirely. Underground adventuring should be hard mode. There is no common language. The major factions of the underdark are confrontational, secretive, evil powers. Like real-world powers, if they need to trade or establish diplomatic relations with another power, they will train translators or use magic. Adventurers will need to do likewise. 

Three big factions. The main languages spoken in the underdark are Elvish (by the drow), Dwarvish (because Dwarvish script can tie together the duergar, the fomorians, and the deep gnomes) and Deep Speech (for the aberrations and mindflayers).

Deep Speech identity. Making Deep Speech a key underdark language solves a lot of the identity problems it was struggling with in my post about that language. Mindflayers, beholders, aboleth, and other major powers speak it, and their servants and allies speak dialects or derivations of it.

Something alien. A trade language exists, but it must be fundamentally different. It is not just "underground Common." Consider using, for example, the Silent Tongue/Speech of Veins of the Earth: “A subtle and expressive language composed of minor or near-invisible bodyshifts, slow twitching of the fingers, seemingly-passive glances, shifts in breathing and complex flows of facial expression. A kind of stealth sign language, common to intelligent travellers and high-status individuals in the Veins."

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