“Dungeons are easy to run because they constrain characters choice.”
This isn’t wholly accurate. A character in a corridor has lots of choices (sit down, dig a hole in the wall, climb on a buddy’s back and search the ceiling). What is constrained are productive choices: you can try hundreds of things, but they only two choices that will make a difference are going forward or going backwards.
By correlation, urban adventures don’t need to be difficult to run, as long as a judge pins down which choices produce results. You map these choices with a flowchart, which ends up looking just like a dungeon. It’s not mapping physical space, but – in the case of urban investigations – mapping clues.
For emphasis: PCs in the city can do a thousand things. But they don’t make any progress unless they follow the clues forward or go backwards.
A dungeon is a flowchart.
A flowchart is a dungeon.
As in a dungeon, some clues lead to dead ends. Some are tapped. Some lead to combat. Some are even hidden by “secret doors” that requiring puzzling out.
And, as in a complex dungeon / mystery, deeper levels transform the landscape. Moving to a deeper dungeon level can be a function of time (the bad guys are continuing to murder people) or due to PC actions, analogous to pulling levers, falling down pits, etc.
To really strain the metaphor, ala the old school dungeon, each level is a new onion skin of the conspiracy. You caught the murderer by clearing out the first level of the map. But who hired him? Why? Do you press into the second level of the map, investigating the next, more dangerous level, or do you retreat back to the safety of town / ignorance? And do the monsters come out after you?
Finally, just like in a dungeon, this only really works if the PCs have vested interest in solving the mystery.
World’s Simplest Clue Crawl: Railroad to the House of Red Silks
The overlord’s son goes missing; the PCs find him dead in their inn room. The Watch is hunting for him and the clock is ticking. It’s a matter of time before someone snitches, the PCs are caught and hung from the Gaol walls.
The PCs have a choice: they can quit the city and never return, or solve the mystery and clear their names.
Player Start: The PCs return from a night of post-dungeon debauchery to find the overlord’s son – apparently beaten to death – in their inn room.
(Remember, the PCs take any actions they want, but following these clues are the only ones that produce relevant results.)
Bloody tracks (A-1) lead from the chamber to another room .
Drunk slavers (B-1) report seeing a woman fleeing the PCs’ chamber just before the PCs returned.
Close investigation (secret door) reveals that the prince was already dead when he was beaten. The real cause of death was a rare opiate that can only be had from Cune the Apothecary (C-1).
Events: The city is not static while the PCs perform their investigations. Use the following timeline to rough out developments, adjusting for PC actions:
Morning: Word leaks back to the Watch that the imperial prince was seen at the PCs’ tavern the night before.
Noon: The Watch raids the PCs’ rooms. Hereafter all encounters with the watch risk the PCs’ apprehension.
Nightfall: A bounty of 100 gp is declared for the apprehension of the PCs. Bounty hunters and thief-takers the city over take notice. By dawn the next day undisguised PCs are readily recognized and assaulted.
A-1 – Bloody Tracks: PCs follow the bloody tracks lead to another inn room. The door is bolted from within. A bloody mace wrapped is wrapped in a cloak and stuffed beneath in the straw bed mat. The mace is stamped with the forge-mark of the Watch’s smithy (A-2).
The window to the chamber is open; bloody tracks on the sill lead onto the stable roof. Further tracks vanish in the mud below.
If queried, the innkeeper can confirm the room was paid for a month in advance by a link-boy the day before. Bribed, the innkeeper identifies the boy as Laraeo, known to run errands for the blackguards drinking at the Sign of the Bloody Boar (B-2).
A-2 – Watch Armourer: The aged Armourer refuses to speak about Watch-business to adventurers and cannot be bribed. Questioning him without raising the alarm will require subterfuge or spells.
However, he can confirm the mace belongs to the watch; he can also share that at the this morning’s inspection all the Watchmen had their maces. The forgetful old man must be prompted to recall that Captain Tibentius (A-3) was reported sick abed and didn’t attend the inspection.
A-3 – The Missing Captain: As in A-2, the PCs will need to employ subterfuge or spells in order to search the Captain’s quarters. Alas, Captain Tibentius is nowhere to be found. His armor, weapons and uniform are all missing. His footlocker is trapped: opened, it releases a lesser devil that attacks the PCs for 1d3 rounds before flying out the window, fleeing back to its master. If the PCs manage to track or give chase, the devil leads them to the House of the Red Silks (D-1).
Questioning soldiers in his company reveals that the commander has been spending his time with a woman, Akiret, at the Sign of the Bloody Boar (B-2).
B-1 – Drunk Slavers: The slavers identify the woman as Akiret – a former prostitute who is now the companion to Captain Tibentius of the Watch (A-3). Akiret is known to keep her quarters in a small room above the Sign of the Bloody Boar (B-2).
B-2 – The Bloody Boar: The alley-dive known as the Bloody Boar is nearly empty, day or night, making the PCs especially conspicuous. A trio of hired thugs lounge at the back of the tavern and try to frighten the PC away. Once violence erupts, another two thugs descend from upstairs, attempting surprise attacks.
Interrogated, the thugs reveal that they were hired by Akiret, who has been holed up in the second-story room (B-3) since last night.
B-3 – Akiret’s Apartment: The PCs discover the body of Akiret, frozen in state of terror. She has a pipe packed with still smoldering summoner’s gum – a rare opiate that relieves its user of fears … by releasing them into the world as devils. Only one merchant in the entire city deals in the illegal paste: Cune the Apothecary (C-1).
The devil responsible for Akiret’s death still lurks in the corner of the chamber, attacking the PCs if they threaten to extinguish the pipe.
C-1 – Cune the Apothecary: The PCs find the store shuttered. If it is still before dusk on the first day, Cune is inside, hurriedly packing his meager belongings, with the intent to flee during the night. The apothecary has learned of the prince’s death and suspects the real reason behind his demise.
If promised his freedom, he shares that he sold his entire supply of summoner’s gum to Captain Tibentius (A-3) at the House of the Red Silks (D-1).
If the PCs arrive after dusk, Cune has already fled, and is killed trying to flee the city. A search of the shop reveals a bill of sale to the House of the Red Silks (D-1).
D-1 – House of Red Silks: The ladies of the House refuse to deal with the PCs unless heavily bribed. If the PCs attempt coercion, they are set upon by the towering eunuchs that defend the House. The mistress of the House, Dame Dama, knows that Captain Tibentius is holed up upstairs, awaiting a messenger. (In truth, he is awaiting payment for the death of the prince and for setting up the PCs).
Any violence alerts the Captain, causing him to flee the House. If the PCs manage to catch the Captain, he digs out his pipe even as he fights for his freedom. Taking one last hit of the summoner’s gum grants him the courage to declare his villainy (and summon a monstrous devil in the same breath): he and Akiret were hired to assassinate the prince and set-up the PCs.
If the PCs can keep the Captain alive long enough for him to make a public confession, they clear their names. The PCs have carried the day.
However, in order to discover why they were set-up, the adventures will have to press on to Level 2.