I have been doodling a series of maps while I try to find the mojo to start on a much bigger dungeon system. Here is one I did today detailing a series of caves used by a local group of bandits. It is going to be generic no DCs, bandit stats, or treasure list use it to fit your needs. Trying to get the old school feel pumping through my veins again.
Cave 1: Large room three cots, small fire ring, three barrels, Smaller room: makeshift desk (planks on barrels), three barrels, empty barrel seat, papers on desk detailing manifests of recently robbed caravan.
Cave 2: Two cots, both side chamber are made to look like cave in piles. If removed each room holds three chests or crates or a combo of the two.
Cave 3: Small crate, three barrels
Cave 4: Two cots and make shift table (boards on barrels). Larger room with fire ring: two logs and fire ring, 14 barrels, surface of underground lake (what mysteries do its depths hold, mwahahahaha).
Cave 5: The Hideout
This cave system serves as the main base of operations for the bandits. The first defensive item is a series of 4 large boulders that will role out and down hill towards the entrance crushing all that are in their path till they pile up in the choke point. You can apply a ref save or whatever you wish to avoid them. The boulders are triggered by a lever which is behind the log wall. Two bandits operate the lever they should be equipped with ranged weapons.
Next item is a pressure plate (DC or notice check or trap sense, etc to detect), if triggered it releases a concealed steal spiked gate. Damage as per your system of choice and reflex save to avoid if you wish.
The “Doghouse” contains a massive (large scale canine, demon dog, etc) it is on enough chain to reach anywhere in the room. If party falls back to ranged attack it it will seek shelter behind the doghouse or just down the corridor they are not occupying.
The room of pillars contains 3′ high stone pillars set about 18″apart. They will slow the movement of all that pass through to half except halfings, or gnomes. They can be walked across (dex, agility, acrobatics etc) at 3/4 or full speed your choice. The room itself has a 15′ high ceiling with three archer positions, they floor of the archer opening is 10′ off the ground. If the PCs crawl through the pillar area it should afford cover but slow them further.
In the large cave after the defenses there is a kitchen area with fire pit and hanging pot, plank table on barrels with barrel chairs, and a barrel prep table. It has a archery range consisting of 3 round hay bail targets 3′ around. The bunk room has cots for 9. There is a secret room which holds high value treasure, 3 large locked chests, 7 large barrels. Behind a wooden door is the bandit leaders room. It contains a large hay mattress on top of 6 crates, a plank desk on barrels, a locked chest and two barrels. Under the crates of the bed is a tunnel that leads back out to the surface. I thought of this after the map was scanned, and I am still knocking the rust off. You can decide it the PCs stand any chance of discovering the secret tunnel. Only the bandit chief and his two Lieutenants know of it, and they will only talk if tortured. Feel free to change, add, subtract whatever you wish.
Admittedly the final cave is really set up to make it hard on the PCs. I may turn this into a DCC funnel since it is a meat grinder. MWAHAHAHAHAHAHAHA.