Late last year, Paizo Kickstarted a superdungeon called “The Emerald Spire“. Along with the characteristicly beautiful production value and stunning art, each of the 16 levels of this detailed module has its own fold-out map in the style of Paizo’s other excellent flip-maps, making it a very easy crawl to run.

I recently decide to host a series of all-day “Retro 80s” Game Days for my players who never had the opportunity to come home from school on Friday afternoons and game non-stop until Sunday night, fueled on little more than Mountain Dew and Cheetos. Since I had backed the Kickstarter at a level where I received all eight double-sided maps as well as the campaign cards, I decided to convert “The Emerald Spire” to 5th edition to use as my old-school dungeon crawl.

The module’s base of operations, Fort Inevitable, requires little conversion as most of the conflicts there are political rather than physical. The dungeon’s levels are designed to equal the PC levels, meaning at 1st level the characters should be able to take on level 1, and by 8th level they should be able to handle level 8. As my players started at level 3, I needed to increase the power of each level a bit.

Below you will find some of my conversions for Level 5, “The Drowned Level”. You will not find detailed information on the Emerald Spire. If you aren’t running “The Emerald Spire”, you may still find these new monsters helpful for your home campaign.

Level 1 “The Tower Ruins”
Level 2 “The Cellar”
Level 3 “The Splinterden”
Level 4 “Godhome”: The majority of this level is roleplaying oriented. Should combat break out, the stats for the associated monsters from the 5th ed Monster Manual work well.
Level 5 “The Drowned Level”
Level 6 “The Clockwork Maze”

New Monsters

Mudlord (CR 5)
Undine Researcher (CR 5)
Minor Water Weird (CR 2)
Fiendish Crab Ally (CR 4)
Swarm of Crabs (CR3)

General Conversions

There are many unique creatures in this level that can be duplicated using the stats of existing 5th edition creatures with few, if any, alterations.

Small/Medium Water Elementals: Substitute the standard Large water elemental for all elementals on this level. Remember, I had my PCs start the 1st encounter at 3rd level so they should be around 7th now.

Giant Moray Eel: The statistics for the Giant Constrictor Snake (MM pg 324) should work well for the giant moray. You may want to include 2 of these monsters as they are only CR 2 beasts.

Bunyip: In place of the bunyip I used a creature inspired by Tribality founder, Shawn Ellsworth, during his recent guest interview on the Dungeon Master’s Block podcast—an aquatic, crab-shelled umberhulk (MM pg 292).

Substitute a 30’ swim speed and the amphibious quality for the standard umberhulk’s burrow speed and tunneler abilities. Also, make sure to describe the beast instead of naming it. Even old school players may not recognize the creature if you don’t call it an “aquatic umberhulk” from the start.

Shark-Tailed Automaton: Use the stats for the automaton on level 3, but grant it a 30’ swim speed.

Mudlord: The mudlord in this module is the result of the Spire’s bizarre magic infusing the decayed remains of four derro with sludge created by pure elemental water. The standard mudlord isn’t that interesting to me so I used the stats for a black pudding (MM pg 241) with the following alterations (CR 5, 1,800xp):

Large elemental undead
AC: 14 (natural)
Speed: 30’; climb 20’; swim 30’
Intelligence 10 (+0), Wisdom 14 (+2), Charisma 10 (+0)
Damage Resistances: bludgeoning and piercing from non-magical weapons
Damage Immunities: acid, cold, lightning, necrotic, slashing
Condition Immunities: exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Languages: Understands Common, Dwarven, and Undercommon. The creature can speak these languages as well, but understanding the slurred and twisted speech requires an Intelligence check with a DC 15. A PC with the Linguist feat gains advantage on this check.
Other: All other ability scores, qualities, and attacks remained the same, including its corrosive form, pseodopod, and splitting ability, though the last is restricted to 4 forms (there were 4 derro spirits infused into the creature). Should the PCs leave the creature behind, any splits that resulted from the combat reform into a single creature within an hour.

Undine Researcher

Medium aquatic humanoid (undine)

Armor Class 14 (mage armor, ring of protection +1)
Hit Points 45 (7d8+7)
Speed 30’; swim 50’
Initiative +5

Str 8 (-1) Dex 10 (+0) Con 12 (+1) Int 14 (+2) Wis 15 (+2) Cha 16 (+3)

Saving Throws Str +0, Dex +1, Con +2, Int +6, Wis +3, Cha +7
Skills Arcane +5; Nature +5; Investigation +5; Perception +5
Senses Passive Perception 15
Languages Aquan, Common
Challenge 5 (1,800xp)

Amphibious. The undine researcher can breath both air and water
Spirit Bond. The undine researcher has a unique bond with his fiendish crab ally. The crab is immune to the damage and effects of the researcher’s spells, it can deliver the shocking grasp cantrip on behalf of the researcher, and when mage armor is cast by the researcher, the crab increases its AC by 3. In addition, the researcher is always considered under the effects of the beast sense spell in regards to his ally.
Summoner. The undine researcher is an expert at summoning extra-planar creatures. If he has a conjuration spell active, he may choose to ignore the concentration requirement of that spell. He may only use this ability for one conjuration spell at a time.

Spellcasting. The undine researcher is a 7th level caster. His spell casting ability is Charisma. He has the following spells prepared:

Cantrips (at will): dancing lights, ray of frost, shocking grasp
1st Level (4 slots): charm person, detect magic, mage armor, shield, thunderwave
2nd Level (3 slots): mirror image, ray of enfeeblement, scorching steam (as scorching ray)
3rd Level (3 slots): conjure woodland creatures, counterspell, hypnotic pattern, lightning bolt
4th Level (1 slot): conjure minor elemental, control water


Multiattack. When the researcher casts ray of frost or shocking grasp he may also make an attack with his kraken’s beak.

Kraken’s Beak. +3 to hit, reach 5’, one target, 1d6 (4) magical piercing, +2d6 (7) piercing damage against fey creatures (including elves and half-elves). Disarm attempts are made at disadvantage.
Ray of Frost. +6 to hit, range 60 feet, 2d8 (9) cold damage, speed reduced by 10 feet for 1 round
Shocking Grasp. +6 to hit, range 5 feet, one target, 2d8 (9) lightning damage, attacks made with advantage against wet targets and targets in metal armor.
Scorching Steam. +6 to hit, range 120 feet, 3 fonts of steam, 2d8 (9) fire/heat damage, +1 font per spell slot above 2nd. Scorching steam is usable underwater but its range is reduced to 60 feet.
Thunderwave. 15 foot cube, DC 14 Constitution save, 2d8 thunder damage and targets pushed 10 feet (half damage and no push on successful save). +1d8 thunder damage per spell slot above 1st.
Lightning Bolt. 100 foot long x 5 foot wide line, DC 14 Dexterity save, 8d6 lightning damage (half on successful save). Creatures standing in water or who are submerged make saves with disadvantage. Flying creatures make saves with advantage. +1d6 damage per spell slot above 3rd.

fey bane kraken’s beak, ring of protection +1, potion of greater healing, scroll of invisibility, scroll of conjure woodland creatures, research journal, scholar’s pack, pearl (100-200gp)


The undine researcher will use his first round to summon 4 crocodiles (CR 1/2, PHB pg 305/MM pg 320) using conjure woodland animals and order them to aid his giant crab eidolon in attacking the party. On his second round he will cast hypnotic pattern and order his creatures not to attack anyone charmed by the spell. On his third round he will use conjure minor elemental to summon 8 steam mephitis (CR 1/4, MM pg 217) using his summoner quality to maintain the concentration on both conjure spells. On his fourth round he will cast mirror image, then use his damaging spells to assist his summoned creatures.

Undine Researcher Variants

There are three undine researchers on this level, a mix of male and female siblings. You can use the previous stat-block for all three researchers, but to prevent the encounters from feeling repetitive you can change each creature’s tactics and equipment to make things more interesting.

You can easily vary the researcher’s kraken’s beak shortswords to better fit your players. Options include substituting a +1 bonus to attack and damage rolls or the vicious quality for the fey bane quality. You can also give each weapon a minor property and quirk from the tables in the DMG (pg 143).  I highly recommend the last option for all three weapons, perhaps developing a similar sibling rivalry between the weapons as there was between their original owners.

A researcher in a flooded area can summon a hunter shark (MM pg 330), a giant constrictor snake (with the amphibious quality, MM pg 324), 2 giant octopuses (MM pg 326), or 4 reef sharks (PHB pg 309/MM pg 336) in place of the 4 crocodiles. Replace the steam mephits with 4 ice mephits (MM pg 215) or one minor water weird.

Water Weird, Minor, MM pg 299: Reduce the standard water weird’s size to Medium, HP to 40 (7d10+7), reach to 5’, escape DC to 12, and damage to 10 (2d6+3). Because of the debris found in most of the water of this level, allow your PCs a DC 20 Perception check as a bonus action to detect the creature even when its invisible.

Fiendish Crab Ally

Medium monstrosity

Armor Class 18 (natural, mage armor)
Hit Points 60 (7d8+14)
Speed 30’; swim 30’
Initiative +3

Str 16 (+3) Dex 16 (+3) Con 14 (+2) Int 7 (-2) Wis 10 (+0) Cha 11 (+0)

Damage Resistances necrotic, poison
Skills Athletics (+6); Stealth (+6)
Senses Blindsight 30’; Passive Perception 10
Challenge 4 (1,100xp)

Amphibious. The fiendish crab can breath both air and water


Multiattack. The fiendish crab makes two attacks with its claws.

Claw. +6 to hit, reach 5’, one target, 1d6+3 (7) bludgeoning damage plus 1d8 (5) necrotic damage, and the target is grappled (DC 16 Athletics or Acrobatics to escape). Each claw may grapple one target. If a creature is grappled at the beginning of the crab’s turn, the target takes claw damage automatically in place of one of the crab’s attacks. If the crab has someone grappled when used to deliver a shocking grasp, the spell hits the grappled target automatically.

The swarm of crabs in the original module is a CR 4 monster intended to fight level 5 PCs. Since my PCs were level 7 coming into this level, I used two of these swarms and was prepared to add a swarm to any combat that didn’t have enough drama.

Swarm of Crabs

Large swarm of tiny beasts

Armor Class 14 (natural)
Hit Points 40 (8d8)
Speed 20’; climb 20’; swim 20’
Initiative +1

Str 6 (-2) Dex 14 (+2) Con 10 (+0) Int 1 (-5) Wis 7 (-2) Cha 1 (-5)

Damage Resistances bludgeoning, piercing, slashing
Condition Immunities charmed, frightened, paralyzed, petrified, prone, restrained, stunned
Skills Perception +0
Senses Blindsight 10’; Passive Perception 8
Challenge 3 (700xp)

Amphibious. The crab swarm can breath both air and water

Swarm. The swarm fills a 10 foot by 10 foot square, can occupy another creature’s space and vice versa, and the swarm can move through any opening large enough for a Tiny beast. The swarm can’t regain hit points or gain temporary hit points.



Claws. +5 to hit, reach 0 feet, all targets in the swarm’s space, 10 (4d4) slashing damage and the targets must make a DC 10 Wisdom save. On a failed save, attacks made on the target(s) by creatures other than the swarm are made at advantage until the beginning of the swarm’s next turn.