TSR's module A1, Slave Pits of the Undercity

TSR module A1, Slave Pits of the Undercity, is the first and the most coherent of the Slavers modules: inventive and challenging while being the most sensibly drafted of these disorderly villain lairs.

The history of the series further emerges from a thread on Dragonsfoot remembering the specifics of the GenCon tournament that gave rise to the four A series modules. The temple and dungeon levels of A1 and A2 each were a single, linear adventure. Player groups in the first round were randomly assigned into one of these four qualifiers or a fifth one corresponding to the early section of A3.  From these five, the best-scoring made it to the semifinal and final rounds, which respectively used versions of the later (city) part of A3, and all of A4.

From such a genesis we can trace the design of Slave Pits of the Undercity (and here, perforce, the spoilers begin). Helpfully for our archaeology, the module includes the original tournament railroad maps for the top and dungeon levels.

New monsters, meant as a surprise, were regularly "spoiled" on the A series covers - here, the aspis

TEMPLE LEVEL

The tournament scenario gives the players inside information about a secret door in the wall of the temple. This door is trapped but not guarded - such is the security protocol of a disorderly fortress - and leads to a twisting corridor through an abandoned area of the building. The "railroad" takes the party past some well-set fights, and other situations that act like puzzles without seeming contrived, such as a deceptive plank over a pit, or a combat dilemma involving a new plant monster, the giant sundew, that becomes much easier if the party realizes how the fortress forces manage this menace in its midst. After this gauntlet, the party will run into the actual slaver forces, and these encounters are devised with the same art, combining trickery, interesting combat problems, and traps.

That's the end of the railroad; but even the tournament scenario has a couple of distractions and dead-ends. One of them, a roughly patched wall that if broken through leads to a face-to-face encounter with a basilisk, had the distinction of taking out a player-character in my own 5th edition campaign.  And in the campaign version of the module, more areas are added branching from the tournament path - a stable guarded by slaver forces, a haunted cemetery and a garrison of terrified orcs, and a spacious courtyard, possibly a shortcut, but where more undead lurk. The reissue of the module in 1986 added a gate from this courtyard into the midst of the organized opposition area, further adding options for the attack.

This expansion allows different approaches to the temple complex. Jason Thompson's cartoon walkthrough of the module shows two of these: one party sneaking in through the tournament entrance, the other masquerading as slave-buying customers to go through the front door. Entering by the stables, by the graveyard orc door, or simply climbing the wall in an unguarded spot are also possibilities.

DUNGEON LEVEL

There are ways down from the temple, most obviously at the end of the final boss fight of the temple railroad; but the full module places two more descents to vary play in the dungeon level. This underground jams together four quite different areas: the eponymous slave pits, with slaves, slavers, and minions; a set of caves that hosts a tribe of orcs allied with the slavers; another set of caves that hosts a population of another new monster, the fearsome four-armed insectoid aspis folk; and a network of wet and filthy sewer passages that ties the whole place together.

The railroad version of the dungeon has the players first encountering some nasty larvae in the acidic spawning pool of the aspis; then crossing the sewer to muscle through a protracted fight with most of the orc tribe; then finally engaging the slavers, including some of their aspis allies, before confronting the slaver leader - who, it has to be said, is less formidable and treacherous than the final encounter of the temple. 

The open version develops the aspis zone and has more connections to approach the bad guys. While the temple is infested with ghouls and a wight, the underground is only semi-unruly - these are groups cooperating with the slavers for now, but if a way can be found to communicate, faction bargaining in the classic big-dungeon style can happen.

BEST OF THE SERIES

My current party cleared out most of A1, using a conversion to 5th edition. Running it was a delight -- the combat challenges tough and packed with surprises, but not in a way that felt forced or unfair. The tricks and traps have a gritty, naturalistic feel to them, and the different areas of the complex are balanced between abandoned/haunted, main bad guys, and side factions. We see how the garrison of orcs, half-orcs, and evil humans deals with the unruly forces in their midst - finding a way to tame the sundew, cringing in fear from the haunted cemetery, hiring some of the aspis. This was also the deadliest module of my campaign, claiming two PCs. Probably, this is just due to incautious player mistakes snagging on two of 5th edition's few remaining teeth. One, doppelgangers have an absolutely deadly surprise attack if they can catch a party member alone; two, even with two saves, there is no easy answer to petrification until characters hit ninth level.

As we'll see in the pieces to come, the other A-series modules, in my opinion, are less deft at presenting an unruly stronghold: A2 is ambitious but strained, A3 a mess, and A4 returns to better form but famously hangs on a railroading premise that may not sit well with new-old-school values.