Should Party Pace Be a Player-Facing Mechanic In More Games?

Should PCs in party-based roleplaying games – particularly fantasy dungeoncrawls – more explicitly choose their pace of exploration?

The following is implicit in how I adjudicate situations on the GM side, but it isn’t something that players historically see in a plainly stated way. I infer their pace from the actions they choose, and then rule accordingly. But I’ve been thinking about what it would look like if party pace was a formal, player-facing mechanic. 

I’ll mention advantage/disadvantage here as a shorthand, but equivalent benefits and penalties could easily be substituted for games that don’t use that mechanic. 

I’m certain this isn’t a brand-new idea. I’m sure there’s are systems and play styles that handles party pace in a similar manner. Pointers appreciated if what I'm describing is very close to something that is already out there.

Methodical. The party is moving very slowly, basically a crawl. 

Assuming ample light and no direct obfuscation, hidden information is typically found without any special action by the party. They have advantage on rolls to find secret information. The party is assumed to be moving stealthily, within reason, and may gain advantage on related rolls.

When moving methodically, the maximum amount of time passes – this is as slow as they can go. A random event is essentially guaranteed, although the party may gain advantage on a surprise roll, or some similar benefit. If there is a clock for antagonist action, or any other time pressure beyond random encounters/events, it will almost certainly advance.

Cautious. The party moves at a slow, steady walking pace.

The party can choose to focus on searching or stealthing, but not both. If the former, as long as they have decent light, they have advantage on rolls to find hidden information. It’s possible to find secret information, but will require pointed inquiry. Stealthing foregoes both the hidden and secret information, but is otherwise practical at this pace.

If some PCs want to search and others want to stealth, they can, but they must split up. Note that stealthing ahead of searchers and searching ahead of stealthers both present complications and dangers for the party. The traditional stealthy-character-scouts-ahead role is, by definition, limited to the Methodical pace.

Balanced. The party moves at a brisk walk.

This is the default party pace. Hidden information can be found with careful questions, but won’t be exposed by default. Secrets are almost never found at this pace. Stealth is difficult or impossible (usually requiring at least disadvantage on an applicable roll).

Fast. The party moves at a hurried pace, like a steady jog, or quick dashes from point to point.

Hidden information and secrets will not be found, but the PCs will still see landmarks. Mapping or orienteering is very difficult (roll with disadvantage, if it is possible at all). Less time passes, but random encounters/events will happen at about the same frequency as the Balanced pace, because the party is more conspicuous. There’s an increased chance for lights to be extinguished and for similar complications. No stealth. If characters moving at a Fast pace run into an encounter that could turn hostile, they probably have a good opportunity to run away. If they give chase to someone who flees from them, they have a good shot at keeping pace with them.

Reckless. The party charges forward, headless of the danger.

Random encounters/events trigger automatically, although there’s at least a good chance the PCs can outrun some of them. Organized non-local antagonist action doesn't really happen because there just isn't much time passing. Players may need to either stow or drop held objects. The party is only dimly aware of their surroundings as they move. No mapping or orienteering. Not only will they miss all hidden and secret information, but they may need to roll just to spot landmarks.

When moving Recklessly, the party can usually escape typical combat encounters (either without a roll, or rolling with advantage), but are likely to be separated or lost when doing so. They have advantage on rolls to escape a pursuer or catch quarry.

Moving at a reckless pace AKA me when I win at Bang! as the Renegade with a Mustang and no other gear AKA I will use any excuse to add Golden Kamuy to a post 

After Them!

We usually don’t care about the pace of monsters or NPCs, but in a chase scenario, it becomes important. PCs or monsters moving a category faster than their pursuer/quarry have advantage on rolls to escape/catch them. PCs or monsters moving two categories faster will escape/catch up as a matter of when, not if. Think about a monster’s abilities when adjudicating this question; some will only use one or two of the movement conditions above. Fleeing from an air elemental should feel dramatically different than fleeing from a giant slug.

Switching Gears

Moving to a faster or slower pace is always possible when conditions are normal and the PCs are in no direct danger. If they are in danger, they can only move down the list, toward the faster paces. Assume they can move by one category per combat round or equivalent unit of time. If a party is moving Methodically and suddenly is drawn into combat, they probably can’t immediately pivot to Fast or Reckless retreat; they need to change pace one stage at a time.

Certain circumstances may almost force them to change their pace. This kind of procedure can add a lot of spice to something like fear effects; frightened characters can only move down in the pace list, toward the faster categories, even if they're not in direct danger (and they may perhaps be compelled to do so, even if other characters do not do the same).

Splitting Time

If the party is moving at different paces, assume that a faster group can take twice as many actions for every step separating them. But they should also get more limited information during that process, in accordance with the landmark/hidden/secret distinctions above.

Player-Facing or Player-Unknown?

I’m always fascinated by which procedures and mechanics are player-facing in a game, and which are not. I don’t think any of the above needs to be player facing. In the old-school context, I endeavor to adjudicate the dungeon’s reaction to the players accordingly, and the players trust me as a fair referee to present the dungeon’s response to their presence in a measured and plausible way. 

But making this mechanism player-facing has a certain appeal for teaching the playstyle to modern players. Divorced from the Strict Time Records of yore, modern/OC/5E-style players will choose to do almost everything Methodically. And why wouldn’t they? What is the incentive to go faster if there are no clocks, no wandering monsters, no proactive enemy responses to their presence? I believe the above procedure, or something like it, can help them grok the pros and cons quite well.

The World's Largest Rewrite: Dungeon Is Wet, Tortoise Foreshadowing, and 30-50 Feral Hogs

Last time: The World’s Largest Rewrite: Salvaging the Core Idea From a Megadungeon Disaster

#104: Sea Serpent (Lesser). Why “lesser”? There is no “greater” sea serpent in the OSE bestiary. Regardless, it is a chance to carve out a water area separate from the giant catfish's pond. One of the big problems with the original WLD, relative to megadungeons like Arden Vul or Thracia, is its flatness; most good megadungeons are three-dimensional, and defined as much by their depth as their breadth. 

We won't worry too much about specifics just yet -- the diagram I posted at the end of the last post is for abstracted, relative positions. But lets assume the lower parts of this dungeon are flooded with seawater, and this was an Alcatraz-style island prison before it became an adventuring site. I like the idea that this part of the dungeon is a possible escape route, but made dangerous by sea creatures that have made their lairs here. The serpent is tough enough to dissuade most of the nearby prisoners from sneaking out this way. The black dragon could probably kill the serpent, but it is too big to fit through the underwater tunnels (and the seawater dilutes the acid too much for it to corrode its way out).

#24: Crab, Giant. Conveniently showing up right after Sea Serpent, we’ll build out our ocean depths a bit more here. We’ll put the crabs a little closer to the core. They scavenge what the sea serpent doesn't eat itself, and are also occasionally consumed by it.

#18: Cat, Great. Rolling randomly for the sub-types once again we get… sabre-toothed tiger. Hell yeah. “Normally only found in Lost World regions.” OK. Maybe part of the purpose of this prison isn’t just to house criminals but also to preserve lost wildlife that no longer exists out in the world. I’m going to put the tiger near the nobles and the catfish – he’s been drawn to the fresh water and stalks the area nearby. There may be a supernatural zoo sub-theme we can explore with other entries.

#81: Nixie. Yeah, nixies are going to require some more dungeon infrastructure and background to explain. I’m beginning to think that entire prison is not just an island, but also overgrown and covered in natural growth on the top, including a large body of fresh water. The nixies were washed in here when the water eroded through the dungeon's ceiling and flooded several regions. The lake where the giant catfish lives is a terminus, but the nixies control the river flowing into it. They’d like to claim control of the lake, but the giant catfish is too big for them to deal with directly. They’ve probably charmed other humanoids, including a few of the noble’s retinue, and perhaps some others we haven’t placed yet.

#62: Insect Swarm. This could go anywhere, couldn’t it? We don’t need to explain why an insect swarm is in the prison, because insects just like to show up in places where they’re not supposed to be. I like how the OSE bestiary has such extensive procedures for encountering them. I’ll draw inspiration from one of those – the rules for escaping the swarm by “diving into water.” Putting them near the water gives the PCs an “out of the frying pan, into the fire” option that might send some of them into the arms of the nixies. I don’t want more bees, so we’re going to go with beetles instead. I think they’re actually plant-eaters and just want to consume the PCs clothes and other textiles, but adventurers won't know that, and their bites through the clothes still hurt!

#133: Wight. It’s interesting that OSE says these are “Corpses of humans or demihumans, possessed by malevolent spirits.” The 2014 5E Manual suggests they are more conventional undead, i.e., the evil spirit is animating the same body it occupied before death. The Monster Overhaul, my current go-to bestiary, emphasizes that “A Wight’s un-life is tied to an oath, a strong emotion, or the simple will to endure.” It has a nice random table of wight types. I rolled on it and got “Avenger.” Perhaps these are enforcers who swore an oath to the prison builders to hunt those who escaped their cells. The oath extends into un-life (oops) and they’re now doing this forever. I think the builders of this prison may be jerks. Per OSE, wights that drain someone of all levels create more wights, so these wights may be “recruiting” more hunters.

I don’t want a whole undead zone where they’re all clustered together, so I’m going to separate these guys from the mummy-zombie zone. We’ll place them in as-yet unexplored territory south of the ochre jelly zone. Mundane acid doesn’t harm them, so they’re safe from the jellies. Presumably they roam around looking for escapees, but their barracks are down there. 

#92: Pixie. OSE treats pixies and sprites as separate things, and while the latter has a bit of a hook to it, pixies are quite boring. The Monster Overhaul lumps them together, but does include some extra flavor we can tap. They are often invisible and have a mercurial, forgetful nature. I like the idea that these invisible troublemakers were accidentally captured when some larger, more important prisoner was detained. That could place them almost anywhere, but the bigger the monster, the more plausible there presence here. I believe they are kind of Tinkerbelling or Jiminycricketing the dragon. The dragon probably finds them annoying, but hasn’t dissolved them yet, because their polymorph ability might come in handy at some point.

#36: Elemental. Picking randomly, we get fire elemental. OSE emphasizes they are summoned servants. Of the prison builder perhaps? I need more detail, so checking the Monster Overhaul, we get some excellent flavor and tables. The “who summoned this elemental?” table suggests tortoise tsar, a Monster Overhaul original, who has some fire-based powers, so fire elemental fits. The tortoise tsar isn’t part of my original conceit of using the OSE bestiary, but I can merge him with the dragon turtle entry. We’ll plan to revisit this situation when we roll up dragon turtle / tortoise tsar and figure out what is going on here.

#15: Caecilia. It’s OK, I had to look it up too. It’s an amphibian that looks like a snake or worm, although OSE’s are 30’ long. To take stock here, all of our monsters so far fit into one of the following categories:

• Prisoners or "zoo" animals
• Invasive species or other intruders
• Guardians or servants of the prison builders
• Creations of other creatures in the dungeon

I want to avoid putting all the monstrous animals in the second category. The prison should still feel prison-like, and not be completely overrun by creatures from outside. I think we’ll say these are prisoners, like our sabre-toothed tiger. Like the big cat, they’re extinct in the outside world (probably for the best – 30’ long, yikes!) but they live on here in the prison. 

#11: Boar. As I said, there’s a lot of beasts in this bestiary. I’m going to tap the Monster Overhaul for inspiration again. It has a table for “local boar crimes,” which is too good to pass up. I rolled “ransacked a granary.” And I note that the Overhaul suggests boars are “as smart as most people.” I like the idea that the prison builders decided these 30-50 feral hogs were smart enough to stand trial for their crimes, just like people would. So they’re prisoners here, recently escaped from their cells, but still trapped within the larger prison. This could go in a sort of Silent Titans direction.

Next time: The World's Largest Rewrite: Floating Heads, Mother Fungus, Cellipedes

The World’s Largest Rewrite: Salvaging the Core Idea From a Megadungeon Disaster

I recently read an exhaustive review from 2013 by oriongates of the World’s Largest Dungeon (WLD for short, hereforth), a megadungeon released for D&D in 2004, at the height of the d20 OGL publishing era.

The product’s gimmick was that it was bigger (and more expensive) than any other dungeon of the time, and that it included every type of monster in the game. This is good advertising and bad design. Reading oriongates’ exhaustive review, it is clear that much of the size is wasted on repetitive, purposeless rooms, and that many of the monsters are shoehorned in to meet the product’s central conceit, rather than appearing because they present interesting challenges and opportunities to tell the story of the place and give the PCs compelling choices for exploration. Compare this to something like Arden Vul (more modern in publication date, more old-school in approach) where the size, shape, and populace of the dungeon is very deliberately communicating something, rather than trying to hit an external, artificial objective.

The WLD would be a mess in any system, but it is particularly ill-suited to D&D 3.5E, where monsters and magic have particularly detailed and complex abilities and mechanics. At least a B/X game could reduce this kind of enterprise to minimalist keys, in the style of Palace of the Vampire Queen. Anything in the D&D-3.5E world has to deal with huge stat blocks and include contingencies for super-powered characters.

Trying to fix this abomination is a fool’s errand. In their review, oriongates mentions trying to do so, but later giving up, and I think that’s the right call. If neither the map nor the lore nor the factions nor the NPCs are really anything to write home about, why would anyone think it was worthwhile to fix? 

I mean, these people somehow delude themselves into thinking it might, but ... But it might work for us.

Update (June 2025): I started writing this post (and subsequent posts about the WLD) in early 2025, and it was mostly done by the spring. It turned out to be a topical exercise, as I later learned that a crowdfunded overhaul of the the WLD is in the works, and as of writing this update, has clocked nearly $700,000. The Backerkit page is extensive, and features lavish production design and a mountain of extras. It also features a long list of contributors with extensive RPG credits. 

While the product certainly looks nice, I am suspicious of language like "Massive in Every Way That Matters." The marketing still sounds very "woooah, Guinness Book of World Records!!" rather than "here's how and why this would be a compelling roleplaying experience." Sheer page count and taxonomic exhaustiveness cannot make up for what really defines a great megadungeon: a specific, gameable concept for an intriguing adventure scenario underpinned by an evocative milieu. 

That said, perhaps the team behind this effort decided that such nuances of dungeon design were simply not right for what is basically get-hype marketing copy, and they will quietly fix the original WLD's many flaws behind the scenes. It will be interesting to monitor the reviews when this beast comes out and see how it does. End of Update.

So, if we were going to try to make our own WLD, we could make life easier by first starting with a smaller monster list. D&D’s bestiary in the 3.5E days was huge, and featured some really weird, niche monsters that could not logically be packed into a megadungeon. Go back to something more fundamental. Start with a classic and basic bestiary, like the OSE monster bestiary. There are 138 monsters here. That is pretty manageable. 

Here’s a list of all those monsters. Look at 'em go!

1. Acolyte 
2. Ape, White 
3. Bandit
4. Basilisk
5. Bat
6. Bear
7. Beetle, Giant
8. Berserker
9. Black Pudding
10. Blink Dog
11. Boar
12. Brigand
13. Buccaneer
14. Bugbear
15. Caecilia
16. Camel
17. Carcass Crawler
18. Cat, Great
19. Cave Locust
20. Centaur
21. Centipede, Giant
22. Chimera
23. Cockatrice
24. Crab, Giant
25. Crocodile
26. Cyclops
27. Dervish
28. Djinni (Lesser)
29. Doppelgänger
30. Dragon
31. Dragon Turtle
32. Driver Ant
33. Dryad
34. Dwarf (Monster)|Dwarf
35. Efreeti (Lesser)
36. Elemental
37. Elephant
38. Elf (Monster)|Elf
39. Ferret, Giant
40. Fish, Giant
41. Gargoyle
42. Gelatinous Cube
43. Ghoul
44. Giant
45. Gnoll
46. Gnome
47. Goblin
48. Golem
49. Gorgon
50. Grey Ooze
51. Green Slime
52. Griffon
53. Halfling (Monster)|Halfling
54. Harpy
55. Hawk
56. Hellhound
57. Herd Animal
58. Hippogriff
59. Hobgoblin
60. Horse
61. Hydra
62. Insect Swarm
63. Invisible Stalker (Monster)|Invisible Stalker
64. Killer Bee
65. Kobold
66. Leech, Giant
67. Living Statue
68. Lizard, Giant
69. Lizard Man
70. Lycanthrope
71. Manticore
72. Mastodon
73. Medium
74. Medusa
75. Merchant
76. Merman
77. Minotaur
78. Mule
79. Mummy
80. Neanderthal (Caveman)
81. Nixie
82. Noble
83. Nomad
84. Normal Human
85. Ochre Jelly
86. Octopus, Giant
87. Ogre
88. Orc
89. Owl Bear
90. Pegasus
91. Pirate
92. Pixie
93. Pterosaur
94. Purple Worm
95. Rat
96. Rhagodessa
97. Rhinoceros
98. Robber Fly
99. Roc
100. Rock Baboon
101. Rust Monster
102. Salamander
103. Scorpion, Giant
104. Sea Serpent (Lesser)
105. Shadow
106. Shark
107. Shrew, Giant
108. Shrieker
109. Skeleton
110. Snake
111. Spectre
112. Spider, Giant
113. Sprite
114. Squid, Giant
115. Stegosaurus
116. Stirge
117. Thoul
118. Titanothere
119. Toad, Giant
120. Trader
121. Treant
122. Triceratops
123. Troglodyte
124. Troll
125. Tyrannosaurus Rex
126. Unicorn
127. Vampire
128. Veteran
129. Warp Beast
130. Water Termite
131. Weasel, Giant
132. Whale
133. Wight
134. Wolf
135. Wraith
136. Wyvern
137. Yellow Mould
138. Zombie

I’m going to randomly pick from this list and put it together as I go. There’s no reason to do this randomly. Randomizing it just makes this exercise more interesting. I mean I certainly don’t want to do this in alphabetical order. No “A is for ape, white as the snow; B is for bandit, after your dough…” No, no, no, absolutely not. Random it is.

Droning Bee by Eric Poslinski

#64: Killer bee. Let’s keep as much of the WLD conceit as possible and assume that this place is (or at some point in the past was) a prison. The OSE killer bees “build hives underground” (interesting) so something about this place attracted them when they were seeking a nesting site. We’ll decide what that was later. But we can definitely imagine a structure of beeswax and propolis that has repurposed and displaced parts of the original dungeon structure. This will give us a good opportunity to add some texture to the dungeon, right from the start; from oriongates’ review, it’s clear that too much of the WLD was plain gray stone.

#29: Doppelganger. The doppelgangers might be prisoners. Thracia has a good encounter with doppelgangers who have been imprisoned behind a sealed-up wall for centuries, which I suppose implied that doppelgangers are immortal and can't starve to death. Perhaps doppelgangers go into a hibernation state when no other sapient bipeds are nearby. Their cells have been covered in hive structure, but they may wake up if PCs or other people get close enough.  

#82: Noble. “Powerful humans with noble titles (e.g. Count, Duke, Knight, etc.)... Squire and retainers: Accompanied by a 2nd level fighter (a squire) and up to ten 1st level fighters (retainers).” OK, I like the idea that this guy and his followers are all prisoners together. Let’s suppose our noble is a Qin Shi Huang type who has done some pretty terrible stuff. The PCs can talk to him, and he will argue that his methods were necessary to unite a kingdom that will last long after his death. 

I like the idea that rather than this being a prison of unambiguously evil creatures like demons and liches, it is more like a real prison, with degrees of culpability, moral gray areas, and judgment calls on the part of the celestial jailers. The PCs will probably not find this noble to be particularly sympathetic… but they might! Or at least they may see him as someone worthy of a temporary alliance or truce. 

He’s here with a cadre of true believers who volunteered to go with him into captivity. Since I already established that the doppelgangers were not near other humanoids, I’m going to put this noble and his retinue on the other side of the bees. The noble and his retinue have been stealing honey to supplement whatever sustenance is otherwise available (we’ll decide later how creatures are getting enough food  to survive here). The killer bee hive provides a nice risk/reward opportunity for NPCs and players alike, since the honey can heal wounds… but the bees also, uh, kill, so it is a dangerous place as well.

#30: Dragon. We’re not messing around. Let's go right to the big guns. I agree with the WLD’s decision not to include every variety within a category of monster, so when we get these monster entries with multiple sub-types, we'll just choose one. I’ll pick randomly and get a black dragon. 

This particularly rapacious dragon has been using its acid breath to slowly burrow out of its cell. The prison was designed to resist this kind of escape attempt, but its structural integrity depended in part on maintenance and monitoring from the jailers, which has since lapsed. The dragon is patient, and it has linked up a number of cells around its primary domain. Like the bees, the dragon provides a reason for the dungeon’s structure to deviate from the sensible, dull, repetitive layout one would expect of a prison. The dragon limits the killer bees’ expansion in this direction, as its scales protect it from their stings, and its acid can easily destroy their hiveworks.

#138: Zombie. There is no real reason to imprison zombies. Another complaint from oriongates' review is that there are too many monsters – particularly the undead – that celestials would just destroy, not imprison. 

So we'll say the zombies were created by something else that is imprisoned here; something more dangerous. Some or perhaps all of them are former members of the noble’s nearby entourage who were killed and then zombified. We’ll figure out later who or what caused that to happen. For now, we'll place our zombies just to the east of the killer bees. They’re indifferent to the stinging insects, so they make a good buffer. 

#16: Camel. From dragons and zombies to… camels. Not all the entries are going to be easy. The camels are not prisoners, and they’re also unlikely to have migrated here intentionally, like the bees did. Let’s say they were brought here by some group of prisoners – possibly our noble and his retinue. We’ll put them adjacent to the dragon’s territory. The dragon has been herding them to supplement whatever food it is getting elsewhere. Humans find them to be irascible, but they freeze like deer in the headlights when the dragon approaches.

#40: Fish, Giant. One of the oddities of old-school D&D is the extensive “unusual animal” entries. I hadn’t realized the OSE bestiary included five different types of giant fish. We’ll pick randomly again for our sub-type, and land on giant catfish. One of the issues with the WLD is that several areas of the dungeon are transparently excuses to cram in monsters who need a custom biome, and the WLD’s “water level” is one of the most conspicuous. We’ll instead presume a number of separate watery areas, several of which may also be connections between different parts of the dungeon, as good megadungeon design necessitates. Water can also help explain the breakdown of separations between dungeon areas. 

We’ll say that this fish was once an ordinary catfish that was sucked into the dungeon as part of a flooding event, and later grew to its abnormal size as a result of the powerful mana suffusing the water within the dungeon. Because it is submerged except when hunting, it is safe from the killer bees, so we’ll put it next to them to form another buffer area. The noble and his entourage probably come here for water; they know to avoid the catfish.

#85: Ochre Jelly. A classic dungeon denizen that can be placed just about anywhere. Since the jelly is acid-themed, we’ll place it near the black dragon’s lair. Perhaps the jellies even originated with the dragon, gradually gaining mobility through latent dungeon magic?

#79: Mummy. We’ll put the mummy near the zombies, and posit that the mummy (whether intentionally or ambiently through its aura of uneath) is what roused them. Obviously this is another prisoner – perhaps the magic that allows it to respawn is particularly pernicious, and the celestials decided to imprison it after failing to find the canopic jar that powered its resurrection cycle. We’ll learn more about the mummy after we place a few more monsters nearby.

#74: Medusa. Gorgons are a favorite of mine. It would be easy enough to just assume this one is a prisoner, but I want to subvert expectations here. Perhaps they were contracted by the builders to help build the dungeon; after all, turning living matter into stone is a good way to supplement whatever stone you’re quarrying. This gorgon was either betrayed by the builders, or trapped here by accident. The gorgon is immortal and at least as willing to negotiate as the noble, if not more so. They can’t turn off their gaze, so they’re a dangerous ally even when attempting to work with diplomatic PCs.

Next time: The World's Largest Rewrite: Dungeon Is Wet, Tortoise Foreshadowing, and Feral Hogs on Trial

More Monster Metamorphoses, Please

More monsters should undergo metamorphosis. Let’s consider some examples, ranging from the canonical, to the reinterpreted, to the brand new.

Piercer to Roper

Some mock the piercer, alleging that its behavior and life cycle is implausible. But I think it is a great monster and makes a lot more sense when you emphasize that piercers grow into ropers. Many animals reproduce by creating many spawn, expecting only a few to survive to adulthood, so a cavern full of piercers in roper territory fits. The piercers also complement the ropers’ tactics; a roper dragging an adventurer toward its maw provides an easy target for some piercers to dive bomb from above.

It always irks me that the 2014 Monster Manual puts the Roper and Piercer in separate entries, while the same book groups the following two creatures in one entry, despite similar immature/mature growth stages…

Fire Snake to Salamander 

Fire snakes have some good flavor (“When a salamander is ready to hatch, it melts its way through the egg’s thick shell and emerges as a fire snake” – that’s good!) But it doesn’t do much to explain how it turns into a salamander. It also is pretty unremarkable as an encounter, with “hot stove, do not touch” as its entire personality.

What if a fire snake consumes heat to turn into a salamander? No big deal on the elemental plane of fire, where heat is plentiful. But on the material plane, it gives them a much more compelling hook for conflict, as they gobble up fires of all shapes and sizes to fuel their transformation.

Gas Spore to Myconid 

The lowly gas spore is another target of mockery for its work-backward-from-dungeon-logic ecology. I don’t think that’s a problem per se, but we can fix it with a non-canonical hack. Instead of assuming that gas spores just produce more gas spores, why not make them the source of new myconid colonies? Either as an intended transition from one life stage to another, or perhaps as myconids hijacking the unintelligent gas spores to spread their colonies?    

One of my favorite takes on myconids, by Dungeons and Drawings

Lurker Above to Trapper

More gimmick monsters from the early days of D&D. These guys have gradually lost ground (or ceiling, respectively) in the game’s cultural consciousness to mimics, which have escaped the confines of D&D to become a fantasy staple (in Dark Souls, of course, but also prominently featured in manga and anime like Dungeon Meshi and Frieren). Thinking about such creatures makes me wonder – does the existence of the executioner’s hood, darkmantle, and cloaker imply that there is some evil pants-mimicking creature out there that can complete the aberrant wardrobe?

Regardless, I do like the implicit idea that camouflaged ceiling monster and camouflaged floor monster might be two parts of the same species' life cycle. Looking at the original AD&D Monster Manual, they’re awfully similar in most respects, but the text doesn’t make the connection explicit. I believe the lurker above is the juvenile form and the trapper is the mature specimen. 

Why? Because of my favorite detail distinguishing them – the lurker above is non-intelligent, but the trapper is “highly” (!) intelligent. 

You, a pleeb, clinging desperately to the ceiling. Me, an intellectual, resting comfortably on the floor. 

Caterkiller to Butcherfly

Here’s an original idea for you. The caterpillar and the butterfly are probably the most famous example of metamorphosis in nature, so let’s monstrify them. The caterkiller is a slow-moving meat shield that loves to consume paper and textiles of all kinds, whether that food is garbage, treasure, or adventurer apparel. 

Coming into conflict with adventurers actually helps trigger the metamorphosis. The “blood” it bleeds from its wounds hardens into a cocoon. Leave a “dead” caterkiller behind, and you will find a pupae when you return. Wait too long before you return, and that pupae will have already split open. A butcherfly now roams the local area, every bit as nimble and savage as the caterkiller was slow and methodical. Remember to tell the PCs the monsters' names. Both forms should behave like tokusatsu monsters and should probably do menacing poses when the PCs first encounter them.