Inspired by a discussion on the Dragonsfoot forums, I decided to try running a D&D game using an expanded version of the Holmes Basic rules. The Holmes Basic boxed set was my introduction to D&D back in 1979, but I almost immediately started playing a chaotic mixture of Holmes and AD&D that gradually evolved into something close to by-the-book AD&D over a period of years. Because my previous experience with them was colored by that AD&D influence, the Holmes rules were both familiar and strange. They included many things I'd overlooked or cast aside for AD&D versions (e.g. ability modifiers, variable weapon damage, et cetera). I knew I'd be house-ruling a bit, but I wanted to try out the game mostly on it's own terms, in a real "old school" manner, and see how it stood up.
That demanded a dungeon, of course, and I decided to go with B4: The Lost City. I'm a fan of Tom Moldvay's adventures, which often draw on fiction for inspiration (e.g. Castle Amber/Clark Ashton Smith, Lost City/Robert E. Howard, Isle of Dread/King Kong); they also tend to offer the DM plenty of room for expansion. Moldvay's adventures are sometimes campaign settings in disguise, and it's amazing how much inspirational material and framework he could pack into a small page count. I'd never run Lost City, and I'd been re-reading the Conan stories, so decided B4 would be the perfect choice.
As the campaign progressed, so did my understanding and appreciation of the OD&D rules. My house-ruled Holmes rules slowly evolved, incorporating bits and pieces from OD&D and its supplements. Eventually, I realized I was not really playing Holmes, anymore; I'd removed almost all the Holmes-specific elements (although I retained the Holmes rules on scroll creation and the movement rate variant) — my game had become OD&D.
B4 is written for the B/X edition of the D&D rules (i.e. the 1981 Basic and Expert sets edited by Moldvay/Cook/Marsh). Obviously, there were a few changes required when running it under a different D&D rules-set, but most of those are so minor that I just handle them on the fly; they're not worth discussing, here. More significant are a few stylistic changes, and a brief description of how I fleshed out the lower levels of the dungeon. This information contains spoilers about the module, and especially about my version of it. If you're playing in my game, you should avoid the marked spoilers, or you'll ruin your fun.
Starting on Tier 5, I began making more frequent changes to the module. As written, it has too many monsters of wildly varied types, for my taste. I'm not a stickler for "must make realistic ecological sense," but in this case I think more uniformity creates a better sense of verisimilitude. I also some minor, but significant, changes to the map.
As written, passage from Tier 3 to Tier 3 happens at 20a, where a ramp descends into the burial chambers/crypts. Unfortunately, it descends into a rather dangerous section of the Tier, and it is very unlikely that the "old god" factions could go this way without running afoul of traps and undead. For example, it seems impossible that the trap at 39 would be untriggered, if this way was used at all. Consequently, I've added a secret trap door in the floor of the central north-south passage. This secret trap door is 40' south of the door to the revolving cooridor, and it leads to a steeply sloping tunnel — almost a chute, though with hand-holds — that ends up at Tier 4, room 35. This addition makes common/frequent passage between Tiers 3 and 4 possible.
As written, passage from Tier 4 to Tier 5 happens through the secret ladder connecting 27A and 44. This is the only access, and it is absolutely necessary for the "old god" factions in the upper tiers to pass this way to-and-from the Lost City, itself. Unfortunately, this means that travel through the chambers of Darius must be fairly common, and this makes no sense. Such traffic would need to pass through areas guarded with living statues, gargoyles, and pit traps It also strikes me as unlikely that the robe of Darius has lain undisturbed on a chair while dozens of people go trooping by it on a regular basis. I think the chambers of Darius should be long-undisturbed, so the map needed to change.
I made the secret door from 45 to 44 a one-way secret door (it can only be opened from room 45). I added a passage leading east from room 44; it ends in a normal (two way) secret door where it intersects the north/south corridor. With this addition, passage between Tiers 4 and 5 can occur without going through the chambers of Darius.
This tier is the temporary home of Demetrios, Bishop of the Temple of Zargon. Demetrios is here (rather than in the city, below), because he was caught plotting against the current Patriarch/High Priest of the Temple and was forced to flee with the followers and mercenaries loyal to him. [yes, that's an addition to the plot.] In addition to hobgoblin mercenaries and loyal Cynidiceans, Demetrios maintains an uneasy alliance with a pack of wererats living on the tier [also an addition to the plot]. The pyramid's entrance hall and main chapel are overrun with rats and giant rats, who thrive due to the presence of water and "manna" in the chapel [I added the "manna"]. The wererats make their home among these creatures. The wererats are well-aware of the "old god" factions and their travel between the Lost City and the upper tiers, but the old god factions are unaware of the wererats, which is how the lycanthropes like it.
There are also several feral subhuman monitors on the level (q.v. Slave Castes of Cynidicea). These brutes fear and hate Cynidiceans, and live off rats and other vermin they kill while hiding in the seldom-visited areas of the tier. Demetrios hopes to gain control over these fearsome creatures, but has not yet attempted to master them.
The original module offers only a bare skeleton for these tiers: maps, monsters, and treasure, but that's about it. If not fleshed-out/changed, this could be a senseless and repetitive crawl (the module points this out, and offers an example of how to flesh out the skeletal structure). Here's an overview of how I'm handling tiers 6-10.
This entire module is an underground adventure (either in the "dungeon" or in the "underdark"). However, this section of the dungeon takes on the role of the "mythic underworld" or "descent into hell." Zargon is an ancient being that embodies chaos (similar to a Lovecraftian Great Old One), and this portion of the dungeon is his domain, and under his direct influence. The source of the madness and chaos comes from here, and tier 10 is the font of it, so the closer you get to Zargon, the weirder and more dangerous things become. Although the module presents this section as little more than a standard dungeon-crawl (tunnels connection rooms that contain various monsters and their treasure), that is not how I'm presenting it. PCs that enter this section of the dungeon will know that they've crossed over into bizarre territory, and there is a chaotic, phantasmagorical, and other-worldly atmosphere to the place. One aspect of a "mythic underworld" is that the heroes "face themselves" (i.e. their weakness and flaws becoming obstacles to overcome). Here, that will become literal, as it is very likely that PCs will be doubled ('Bad Ash') in this section of the adventure.
Monsters/Qualities of this Section:
The aforementioned "slime crawlers" are one way PCs could be doubled. These creatures possess a poisonous bite that renders victims helpless, reduced dream-filled torpor. While victims are helpless, the slime crawler draws some blood (not a lot) and then wanders off to form a pod. The mature pod will contain a double of the PC (no equipment, though).
One encounter in the upper levels of the module is a group of sprites. In my game, these are not typical woodland sprites, but a band of similar fey that live in the fungal forests of the lost city. These sprites are Neutral in outlook, and enjoy playing pranks on the Cynidiceans (and probably on PCs, too). They are not necessarily friendly, but are not actively hostile. They are also excellent sources of information, and can be bribed to get news and information. Consider the following passage from Jack Vance's Dying Earth as inspiration:
Mazirian stopped. The Twk-man looked down stolidly.
"Have you seen a woman of my race passing by, Twk-man?"
"I have seen such a woman," responded the Twk-man after a moment of deliberation.
"Where may she be found?"
"What may I expect for the information?"
"Salt—as much as you can bear away."
The Twk-man flourished his lance. "Salt? No. Liane the Wayfarer provides the chieftain Dandanflores salt for all the tribe."
Mazirian could surmise the services for which the bandit-troubadour paid salt. The Twk-men, flying fast on their dragon-flies, saw all that happened in the forest.
"A vial of oil from my telanxis blooms?"
"Good," said the Twk-man. "Show me the vial."
Mazirian did so.
"She left the trail at the lightning-blasted oak lying a little before you. She made directly for the river valley, the shortest route to the lake."
Mazirian laid the vial beside the dragon-fly and went off toward the river oak. The Twk-man watched him go, then dismounted and lashed the vial to the underside of the dragon-fly, next to the skein of fine haft the woman had given him thus to direct Mazirian.
In keeping with my desire for magic swords to be important items, imbued not only with magical dweomer, but also with spirit, personality, or even full-blown sentience, I'm using the OD&D approach that says all swords have Int and Alignment. Here are my changes to magic swords found in B4:
I've added numerous air shafts and vents built into the upper levels of the pyramid. In addition to air-flow, these also allow sound to travel and mutate over great distances, and allow for the passage of vermin like snakes, rats, insects, lizards, et cetera. They are omnipresent in the upper pyramid. They're usually near the ceilings, and are sometimes incorporated into designs and carvings. Much of the upper pyramid is decorated with stylized carvings in "borders" that run along the ceiling or floor. Usually these are purely decorative, but they sometimes have actual meaning that can offer clues about the location, or they can conceal traps, hidden switches, et cetera.
Sacrifices to Zargon are a common feature of life in the lost city, itself. The first choice is a criminal, but there are few of those (most people are too enraptured in their own dreams to commit or report crimes). Lone followers of the old Gods are sometimes arrested as criminals by the priests of Zargon. The sick and old, especially from slave castes, are the next choice. If none of the above are available, then young children will be chosen, since they're easier to replace than adults. The module mentions wandering Gnomes that arrived through the underdark connections. These unfortunates are the remnants of a gnomish trading expedition that came to grief in the Lost City. They would very much like to see revenge on the priests of Zargon.
Certain types of monsters in the Lost City are associated with Zargon. These include: