Dungeon locations are keyed with the letter 'D'.
- I used elements of the original adventure's background and combined it with the background info for U1 and some of my own material. In this version, Zenopus was the original wizard to occupy the site a century or so ago, and he built the tower and manor house to facilitate exploration of the Dungeon level (the ruins of an ancient complex). The thaumaturgist who has come here now is searching for Zenopus' legacy: an item of great power rumored to be hidden somewhere in the dungeon. I'll get more into the full background notes in a future post.
The original dungeon has the DM insert players at the stairs marked "START." In this version, the entrance stairway can be found hidden by brambles in the Estate Garden (the "mysterious tunnel" mentioned in the head servant's journal, area M18). It is now only one of multiple entrances into the dungeon level.
So far, the party has discovered the secret door to the Sea Caves level in the manor's cellar, the mausoleum shaft (to area D9) in the cemetery on the Estate Grounds, and have learned of the existence of the tunnel entrance (but have not yet found it). I anticipate that they will reach the Dungeon level soon, though they have made a huge detour to explore a "muddy mound" they spotted in the swamp below the manor bluff—the troglodytic entrance to the dungeon portion of N1 Against the Cult of the Reptile God.
Original area C was at the bottom of the entrance stairs and gave the DM some details about dungeon corridors. I increased the width of some of the "main" corridors to 20' (I like wide avenues, which make for more interesting tactical fights during wandering encounters). I also added quite a few staircases, to alter the room elevations and confuse players as to how deep they are below ground.
There was no wandering encounter table in the original manuscript, so I added one with a few relevant monsters (1:6 chance every 6 turns, increasing by +1 if the party uses light and/or makes a lot of noise):
| 2d6 |
Encounter |
| 2 |
1–2 ghouls (see D9)
|
| 3–4 |
2–4 skeletons (D10)
|
| 5–6 |
3–6 goons (D3)
|
| 7–9 |
3–6 giant rats (D10)
|
| 10–11 |
1–3 fiery beetles (D26)
|
| 12 |
Thaumaturgist (D6). He is accompanied by (1d6): 1-3 = 2–6 goons;
4-5 = bodyguard; 6 = 2–4 goons + bodyguard.
|
Area D1 (orig. C) lies at the intersection of two wider corridors. The area is actually the landing at the bottom of the entrance stairs, with three more staircases descending from it in the other directions. This area had no inhabitants in the original key, but I stationed a few goons here as guards.
"Goons" are essentially goblins: misshapen, ugly human scumbags. They serve the thaumaturgist as a brute squad against his rival Sanbalet's pirates. I could have easily kept them as goblins, but goblins were frequent antagonists in the players' previous 5e campaign, so I wanted to change the enemies up a little even if only from a description perspective. I also gave every goon some personal loot: 2–12 cp and 1–8 sp (their payment from the Thaumaturgist who runs this level).
Areas marked D2 (a–i) are empty (orig. E). I typically put debris and detritus in these rooms, dripping ceilings or puddles of water, dungeon vermin fleeing from the party's light, maybe a weird sound or an extra encounter roll. These are rarely just "empty" rooms.
D3 (orig. A) is a gigantic room which really should have some ceiling support. This is the case with many of the larger rooms, so I added pillars to quite a few rooms. In addition to adding to the dungeon's verisimilitude, pillars/columns in dungeons are useful because they can provide cover, break up sight lines, and help conceal sneaky creatures.
The original room had an adjustable number of goblins, scaled to the party's size. (An early attempt at "adventure balance"?) I turned the goblin barracks into a dungeon camp of goons and established a more exact range of 5–12 occupants, but kept the same order-of-battle and treasure as in the original writeup.
D4 (orig. area B) stays pretty much the same, other than the addition of pillars to the room.
D5 (orig. area G) stays the same, except any fleeing giant rats duck into an obvious hole (r), which the party can crawl into and enter the abstracted "rat tunnels" part of the dungeon (see D10). The original treasure is a bag of electrum pieces (which I converted to
gp) and a silver dagger "(c)oncealed in a mass of old bones, chewed
leather straps and bits of armor."
In going through these modules, I kept noticing bits and pieces of adventuring gear like this sprinkled throughout (another good example was the rot grub-infested body in the manor's Wine Cellar, area M20). When we started this adventure, I included a piece of info in the players' overview: a rumor that an adventuring party had recently come to town and traveled to the manor, but were not heard from again. I began tracking some of this treasure as clues to that party's fate, including a couple of survivors.
At one point, the party hired some mercenary fighters to help them, one of whom was female (randomly rolled); I typically ask players to name hirelings and such (as it helps them remember), and one of the players named her "Lenore." I quickly added some background that she was in town searching for her sister, "Lemunda the Lovely," an adventurer who had gone missing. Lenore died in battle, unfortunately, which may prove a poignant moment should the party rescue Lemunda from the pirates down in the Sea Caves.
D6 (orig. area F) is the workshop of a thaumaturgist (4th level Magic-User) who, in the original manuscript, was attempting to "...take over the dungeon level." I named him Vexler and built on his background motivation to have him be: a) specifically searching for area D28 on my expansion map; and b) vying with Sanbalet for control of the site. Vexler loosely "controls" his gang of goons through fear and bribery, but they are easily cowed by others. There is only a 1–2:6 chance he and the bodyguard are here; otherwise, the room is unoccupied.
I named the bodyguard, Barnabus, and had him be a member of the lost adventuring party who was charmed by Vexler, rather than a smuggler as in the original (accounted for by his magic sword and valuable belt). The three statues are other members of that party: two fighters (Dexter and Fred) and a cleric (Brother Hume). It is totally possible to free Barnabus of his charm and somehow transform the stone statues back into men, if the party is lucky/clever enough to figure it out. I also added a partial map of this dungeon level left on the worktable as a bit of treasure, showing the areas Vexler has explored so far in his search for Zenopus' summoning chamber.
D7 (orig. area S) is the basement floor of Zenopus' original tower. It remains mostly the same, though I did not hide the door to D6; instead, I moved the secret door to replace the south door, by which Vexler can descend the stairs to the Sea Caves level, where he spies on the pirates' activities. I also made the 2 HD giant snake (which is not in Holmes Basic) a 4 HD giant python (in LL), since the manuscript makes no mention of a poison save. The upper tower levels (orig. S1 and S2, which in the writeup were just outside Portown) are now part of the Estate Grounds key
D8 (orig. area D) contains the statue/door puzzle and it works in the same manner as described in the manuscript. The only things I added were a Magic Missile trap should someone try to destroy a door (cast as 5th level spell fired from the statue's fingertip; the puzzle "lock" also ceases working until a replacement door is mounted), and a randomized time period for the door to stay in the position the party leaves it, after which it turns to face a new direction.
D9 (orig. area P) is a room I added to the map and placed in an entirely different section of dungeon. The crypt contains the same two ghouls as in the original, but I converted the platinum pieces to silver and gold, and boosted the value of the gems to give a little extra xp. In the central south alcove, a shaft in the ceiling is a dirt tunnel that emerges in one of the small mausoleums in the cemetery on the Estate Grounds above.
The ghouls' former lair (area P) is now the "empty" room D2j on the revised map. As in the original writeup, the door opens into a shaft, but in the floor instead of the ceiling. The pit shaft descends to the Sea Caves level (area S12).
D10 (orig. area N) is another huge room that needed columns. Much of this remains the same, with a few added details. I identified which sarcophagi were already opened (and plundered by goons) and labeled the closed sarcophagi (rather than rolling at random), and provided a way to end the "dancing dagger" effect to recover it as treasure, giving it a 25 gp value. I also changed the chance to encounter giant rats from 50% for 1 rat per turn to 1–2:6 chance for 1–3 rats.
The Rat Tunnels (orig. area RT) are described in the manuscript as "an endless maze" (tight tunnels, difficult to fight in) and abstracted mechanically as random chances every set number of feet to encounter another rat or discover a few coins. The rat tunnels are written like a death trap with virtually no way out, save for two potential exits (without any indication how a
party might arrive at one of them, and with the other one drawn on the map but leading nowhere interesting).
In writing his expansion of the Sample Dungeon (The Forgotten Smugglers' Caves), Zach Howard took this abstraction idea and designed a similar area, but one which resulted in a much more interactive maze that (eventually) exits into other areas of the dungeon. I took that model and redesigned the rat tunnels to work as follows: For each turn the party spends in the tunnels, there is a 1–2:6 chance to encounter 1–3 giant rats. Regardless of the encounter result for that turn, the party also rolls 2d6, adding the total number of turns they've spent in the tunnels, and checking the total on the following table:
| Total |
Result |
| 3–7 |
Wander aimlessly. |
| 8–9 |
Find a piece of adventuring gear of poor / damaged quality, but usable (1d6):
1 = rusty knife;
2 = bent iron spike;
3 = half-burnt torch;
4 = single lockpick;
5 = 7 ft. frayed rope;
6 = sack with a small hole in it.
|
| 10 |
Find valuables (1d6):
1–2 = 1d6 cp;
3–4 = 1d6 sp;
5 = 1d6 gp;
6 = small jewelry (1d10 x 10 gpv) |
| 11–12 |
Find human or animal bones. |
| 13–17 |
Wander aimlessly. |
| 18 |
Find valuables (1d6):
1 = 1d6 sp;
2–3 = 1d6 gp;
4–5 = jewelry (3d6 x 50 gpv);
6 = gem (1d10 x 50 gpv) |
| 19+ |
Find a rat hole exiting the tunnels in a random location (1d6):
1 = inside the house (ground floor);
2–3 = outside (gardens);
4–5 = on the Dungeon level;
6 = in the Forgotten Caves. |
D11 is a new map location. The north and east corridors show signs of recent excavation (broken tools, dig leavings, etc.), leading to my expansion of the dungeon (rooms D15–D28). In addition, a nearby alcove (a) contains a fearsome gargoyle statue, claws poised and fanged maw open.
A hidden button in the back of the gargoyle's throat causes a secret door on the back wall of the alcove to slide open for 1 round. A small chamber beyond (b) contains two bronze pedals protruding from wall housings near the floor. Depressing the pedal on the north wall opens the eastern secret panel; depressing the south pedal opens the western secret door into the pirate's stairway between M21 and S12. Only one of these doors may be open at any given time.
D12 (orig. area J) is descriptively the same, though I lowered the ceiling height to 20 ft. I also converted the "enormous spider" into a standard giant black widow spider (LL). The original version is a TPK machine: AC 3, 6 HD, and a -1 penalty to saves vs its insta-death poison. This thing would dominate the dungeon level, which I like in general, but in this case I didn't want it to be such a huge presence, especially with such paltry treasure. To keep this encounter sufficiently terrifying, however, I kept this spider's save-or-die poison (unlike the weaker venomous creatures found in the manor house).
D13 (orig. area H) remains fundamentally the same, though I modified some of the mechanics Dr. Holmes wrote into the module. I love that he showed aspiring DMs (like me, bitd) examples of how you can modify the rules or create new ones as needed (the enormous spider in area J is another good example), but the mechanics he came up with for this area aren't terrific.
I changed the hazard to: Anyone who enters the river channel while encumbered or wearing armor of any kind sinks to the bottom until they remove it. A character can hold their breath for 1d4 rounds + their Constitution / 3. To remove a set of armor takes 12 rounds – base AC (including shield, if applicable); thus, removing chain and shield (AC 4) takes 8 rounds. When the character's breath gives out, they take 1d10 damage each round thereafter and must make a save vs. Breath (at -1 cumulative per round), or fall unconscious and likely drown.
D14 (orig. area I) remains the same as the original manuscript. The east passage leads to a long, roughly cut stone stairway down to room S1 on the Sea Caves level. The rest of the Sample Dungeon rooms (K, L, and M) have moved to the Sea Caves level at the base of the bluff as rooms S2, S1, and S3 respectively.
D15 is my first expansion chamber. In this crumbling room is a second camp of 4–12 goons, a crew of diggers exploring these newly-discovered chambers. They experience high levels of anxiety and paranoia due to their proximity to the unknown (they fight at +1 to hit, but their morale checks are at +2 to fail). The east door is boarded shut from this side (due to the haunting sounds in D24).
D16 is empty, with mildew-streaked walls carved with marching fish-men who carry weapons, banners, or offering bowls filled with treasure. The south wall has collapsed, with visible rat tunnel openings (same as D10, including the chance for a giant rat encounter). Anyone listening at the west door (or opening it) hears the sounds of splashing water. A secret door on the north wall is opened by depressing the carved head of a fish man with a star for an eye (the wall panel pushes in and slides to the left)
D17 is another empty chamber, with a bronze hatch in the floor near the north wall. Twenty feet below the hatch is the floor of area F11 on the Forgotten Caves level. A broken pile of ancient timbers is all that remains of a wooden staircase that once connected the chambers; something glimmers green in the wreckage.
D18 is a "sunken" chamber, with staircases at each entry corridor descending 10 ft. into the flooded room. A thick stone pedestal (3 ft diam, 2 ft high) stands in the center, supporting a statue of an arcing fish. Water gushes from the statue's open mouth, spilling onto the pedestal and then the floor, where it has collected in a pool of clear, fresh water (approx. 18" deep) that covers the entire floor and the last few steps of each entrance stair. Sodden piles of debris and a carpet of slimy algae can be seen beneath the surface, and small silver fish dart about. Below the scum of algae is a beautifully-tiled floor. The algae also conceals a +1 Trident of Fish Command in the southwest corner. The pool empties into the north passage—another descending staircase.
D19 is a shrine to an evil fish-god. Cold water cascades down the stairs from D18, which disappear beneath the surface of another flooded room (4 ft. deep). A gruesome, 9-ft. high statue of a creature with the body and head of a grouper-like fish, and the arms and legs of a human, including webbed, clawed hands and feet, stands waist-deep against the north wall.
The water is filled with a school of ravenous piranha (AC 8; MV 120/40; HD 3; HP 20; AT 1 bite per target in the water (attacks as 2 HD below 50% hp; as 1 HD below 25% hp); D 3–12 at full hp; 2–8 at 50% hp; 1–4 at 25% or less; SD all weapon damage is divided by 10 and applied as decimals to the total (i.e., it takes 200 hp of weapon damage to kill the school); magic damage is applied 1:1; M12; XP 50).
Hidden beneath the water before the statue is a coral altar with a huge clam shell (closed). Prying the shell open takes 1–4 rounds and requires an Open Doors check at -1. Inside is a Torc of Frenzy, made of a shark's lower jaw hung on a golden chain. Anyone wearing it gains a bonus of +1 to all melee damage, but becomes frenzied upon drawing an opponent's blood in battle. The wearer does an additional +1 damage (+2 total) to that opponent (though they can target a different creature). The wearer cannot leave melee engagement, however—even if they are about to die—until they either make a save vs. Spells, or all engaged enemies are dead. The additional +1 damage can only apply to one enemy in any round, but if the torc's wearer attacks a different target and hits, the damage bonus now applies to the new target.
D20 is an isolated section of ruins inhabited by a gelatinous cube. It roams the 20-ft. wide collapsed corridors to the south and west of D18 (it does not descend either staircase, however), as well as the corridors leading into and out of area D20. It may also be in room D20 (determine its location randomly at any time). It feeds mostly on rats, but the first time the party first “sees” it, the remains of a recent goon victim hang suspended in the gel. The goon's bones are mostly dissolved, but what's left still supports its helmet, hide armor and boots, short sword and shield, making it appear as though a skeletal fighter approaches.
Other than the goon's personal loot, there is no other treasure in the cube. In room D20, however, a 10-ft high ledge holds a bronze box containing: 190 gp and a Potion of Extra-Healing.
D21 is partially collapsed, with a huge pile of ceiling rubble in the northwest corner. A pair of 12-ft. high doors plated with patinaed copper stand on the east wall. The doors are engraved with a message in an old Common script: “Woe to the unworthy who come before me.” The heavy doors are unlocked, but the hinges are corroded, requiring a combined Strength of 25 to push open.
D22 is a wide hall with six alcoves, three each on the north and south walls. A marble statue of a nude warrior-woman brandishing a (real) copper sword or spear (50/50) stands upon a plinth in each alcove. Each statue also wears a gold necklace with a jeweled pendant. Another pair of tarnished copper doors stand on the far end of the hall. These are engraved with a message in old Common: "Bow down before your master or face my wrath."
The gold-and-jeweled necklaces are quite valuable and easily removed (top, l–r): aquamarine (600 gpv), black pearl* (600 gpv), red spinel (200 gpv); (bottom l–r): amethyst (200 gpv), violet garnet (600 gpv), topaz (600 gpv).
The black pearl is cursed. Whomever bears it must save vs. Spells each day; if failed, they must possess it forever. The cursed subject becomes paranoid, irritable and nasty, losing 1 to their CHA score, plus 2 more over the first month they possess it. The subject will transform into a fish-folk over the six months after that. The only way to end the curse is to return the black pearl to the clamshell altar in D19 (though any CHA loss is permanent).
D23 is a throne room. A rotting red floor runner spans the length of the room, from the west doors to the dais of a stone throne. The chair's arms are carved into the shape of leering dragon's heads, while the back is mounted with a carved pentacle surrounded by arcane runes. Rotting tapestries hang on the walls. The doors to either side of the throne are painted with images of fierce warriors.
On each arm of the throne are three arcane runes inlaid in silver (6 total). Anyone sitting in the throne who touches a rune causes it to glow; touching it again activates a throne power:
| L1 |
Nothing (but both L1 and R1 light up.)* |
| L2 |
A 15'x15' cone of fire erupts from the left dragon's head, doing 10 damage (save vs. Spells for half damage). This power can activate three times per 24 hours. |
| L3 |
A 60'x5' lightning bolt (5x60 ft; D 10d6) fires from the pentacle straight up the carpet, doing 10d6 damage (save vs. Spells for half damage; the throne-sitter is unharmed). This power can only activate once per 24 hours. (R3 also lights up.)** |
| R1 |
Nothing (but both R1 and L1 light up.)* |
| R2 |
A 50'x50' cone of frost erupts from the right dragon's head, doing 1d4+10 damage (save vs. Spells for half damage). This power can activate three times per 24 hours. |
| R3 |
Nothing (but both R3 and L3 light up.)** |
| | |
|
*Touching both simultaneously summons two phantom warriors (AC 4; MV 120/40; HD 2+2; HP 12 ea.; AT longsword; D 1–8; SD undead, magic weapons req. to hit, turned as a 5 HD creature; M12; XP 83 ea.), who step forth from the warrior images on the doors. They defend the throne area, attacking anyone in the room not sitting on the chair. Touching both symbols simultaneously again returns the warriors to their respective doors. |
|
|
**Touching both simultaneously causes a secret drawer in the throne's base to slide open. Within the compartment is a nicely-folded, deep blue linen robe, decorated with embroidered
arcane symbols and astrological signs in gold thread, and a conical hat
with a wide brim (same color and designs). Resting on top of the folded
robes is a Chime of Opening with 7 charges (see D27), a thick iron key (see D26 and D28), and a rectangular copper plate inscribed with the word "Haximaxial" (see D23a). |
D23a is a wide alcove area behind the throne. A narrow, circular groove (20' diam.) is cut into the floor. Mounted on the west wall is a 4' diam. copper plate, hammered into a grim-looking demonic face. When someone steps into the circular area “inscribed” in the alcove floor, a Magic Mouth appears on the copper face, demanding: “Speak the word!” If someone says, “Haximaxial,” the circular area becomes an elevator that descends to the dungeon sub-level, where Zenopus met his doom.
I have not designed this area yet because the characters are nowhere close to coming here (and there's a decent chance they may never find the secret elevator). I have some ideas for this sub-level, but I'm not ready to finalize anything. This is a bridge I will cross later, if necessary.
D24 is stocked with broken and rusted torture devices (rack, stocks, table with tools, etc.). A cold firepit in the northwest corner is filled with ashes; several branding irons and pokers are propped on the rim. A rusted-shut iron maiden stands against the north wall. An iron lever juts from a housing on the west wall, near the corridor (the lever is in the "down" position).
Each turn spent in room has a 1–2:6 chance for bloodcurdling screams and cries of pain to fill the room for 1–4 rounds. Searching through the ashes in the firepit uncovers a ring of six iron keys which open the cells in D25.
If the iron lever is cranked to the “up” position, the doors of the iron maiden swing open, releasing a mutilated zombie. The zombie wears a gold necklace with a large tourmaline (150 gpv) and a Ring of Shielding (enables the wearer to cast the Shield spell once per day). There is a 1:6 chance each round that the zombie’s ring activates spontaneously (giving it AC 4 or 2 vs. missiles).
D25 is a series of prison cells, each behind a stout wooden door with a narrow, barred window and an iron padlock (opened with the keys in D24). Each cell is bare, save for iron manacles bolted to the walls, some scattered straw on the floor, and wooden bowls and tin cups. The center cell to the north is inhabited by a ghoul, who has been here "...for so long." The pitiful creature begs the party to release him; in exchange, he offers to escort them to “a great treasure.” He will actually lead them to D9.
D26 is lit by a natural seam of brightly-glowing, orange-red crystals that slashes across the southeast wall. Dozens of fist-sized beetles swarm over the seam, slowly eating the crystals; six hound-sized, glowing beetles also scuttle about. The door on the south wall is made of rusted iron.
The crystal seam radiates intense heat. Anyone within 20 ft. of the southeast wall takes 1 damage per round (no save); anyone within 10 ft. takes 2 damage per round. There is a 1:6 chance each round the characters are within 30 ft. of the east wall that the larger beetles take notice of the party, causing 1–6 of the fiery beetles (AC 4; MV 120/40; HD 1+2; HP 5, 2x6, 7, 2x8; AT 1 bite; D 2–8; SA heat aura (5 ft.) causes 1 damage per round (no save); ML 7; XP 21 ea.) to approach hungrily.
The iron door is painfully hot from its proximity to the crystals (–20% to pick lock, plus 1 damage per round). The key to this door can be found in D23. The corridor beyond is a staircase down to the Sea Caves level (S20).
Someone could use the Potion of Fire Resistance in D27 to approach the crystals without harm and remove up to 10x crystalline "shards" (approx. the size of an iron spike). A shard remains warm but does no damage unless it is placed in contact with two or more other shards, at which point the 3 shards generate a 5' heat aura (as above); every 3 additional shards touching increases the aura by a radius of 5'). If a shard is thrown against a hard object, it explodes in a blast of heat (2d6 damage in a 10-ft. diam. area).
Should a character attempt to "mine" more crystal from the seam by striking it with a tool, they trigger a 10 HD fireball (as spell) centered on their location. In addition, there is a 1–2:6 chance that another fireball is triggered the following round in a different section of the seam, a process that repeats until either no more fireballs explode or 5 of them do, at which point, a massive explosion destroys the eastern part of the bluff, forming a 200-ft. diameter crater on the Dungeon level, the Manor, and the Estate Grounds. The blast rips upward so the lower levels do not collapse, though seismic fractures appear in the stonework.
D27 is empty save for a large stone chest (a featureless rectangular box with flat lid) against the south wall. A smoke-colored cat sits atop the chest licking its paw. When someone enters, the cat stands and meows.
When anyone approaches within 10 ft. of the chest, the cat hisses menacingly, then yowls if they continue to advance. Anyone trying to touch the cat or chest gets a warning scratch first. If someone wearing the robes and hat from D23 enters, the cat hops down
from the chest and rubs against them, purring constantly. It does not
leave the room, however, but resumes its duty atop the chest when the
party exits.
The cat attacks anyone who attacks it or attempts to disturb the chest. It will move off the lid to attack, but prioritizes targets who try to mess with the box. The cat is a guardian familiar (FF: AC 8*; MV 120/40*; HD 1*; HP 5*; AT 2 claws, 1 bite; D 1–4*/1–4*/1–6*; MR 50%; M12; XP var).
*The guardian has nine lives. Each time it is slain, up to the ninth time, it is instantaneously reborn, stronger than before. At each rebirth, add +1 to its AC and HD, +20 to MV, +1–8 HP, and +1 damage to each attack. It has a separate XP award each time it is killed, as well.
The lid of the chest has Hold Portal cast on it (as 10th level), but opens easily by using a charge from the Chime of Opening (D23); inside are the following items: 50 gold bars (50 gpv ea.), Bracers of Defense (AC 4), an Elixir of Life (as Raise Dead spell), and 2x Potions of Fire Resistance.
D28 is hidden behind a secret door (removing a loose wall brick reveals a niche and a lever that causes the adjacent wall panel to swing open). Beyond it is a small chamber with a similar lever protruding from the east wall and a locked iron door (–20% to pick; –2 to force open) to the south. The second lever opens/closes the secret door from this side, while the iron door is opened with iron key in D23.
The irregularly-shaped room behind the door is a summoning chamber. A dozen 5-ft. high black iron candelabra with 7x blood-red candles in each line the angled walls. Two arcane circles are precisely drawn on the floor in silvery chalk. Arcane spell-casters recognize the south circle as a thaumaturgic summoning circle (of elemental water), within which rests a 3' diam. copper basin filled with water. The north circle is a protection circle, within which stands a stone lectern bearing a heavy tome.
Stepping into the protection circle causes the candles to ignite, filling the room with red light. The book is a Tome of Conjuring Water Elementals that enables the wielder to cast the 5th-level spell and summon an 8HD water elemental. The summoner may use this chamber—or another like it—to call forth the elemental from the water basin and then bind it to the tome (a dangerous and expensive ritual).
The summoner must first prepare offerings of powdered gems and magical admixtures worth 1,000 gp, which are consumed when cast into the basin. They
must then roll their INT or less on 1d20, at a penalty of –1 per experience
level lacking if the summoner is not of a sufficient level to cast 5th level spells. If the INT roll fails, the elemental escapes its magical restraints for 1–4 rounds, during which it will attack the character and any other enemies in range. When this duration expires, the elemental returns to its home plane and the book is destroyed.
If successful, however, the wielder can thereafter use the book once per day to summon the elemental, as if reading the spell from a scroll. If not of a sufficient level to cast 5th level spells, however, they must still roll make an INT check (as above). If failed, the summoning does not work and the use of the book is lost for the day. If the book is ever destroyed, the pact is broken.
Unlike the spell, the elemental returns to its plane if the summoner’s concentration is broken (or they choose to end it), so long as the summoner still possesses the book. If the elemental is present when the summoner loses possession, the elemental will turn on them. If the elemental is ever killed on this plane, the pact is broken and the tome loses its power.
One final change I made to the overall map alignment, once I got everything in place, was to shift the cellar foundation over a smidge, like so:
