OK, so wandering monsters are an integral part of old-school dungeoncrawling because they put a price on each unit of exploration/time spent in the dungeon; and mapping and movement rates are important because they relate to time in the dungeon, which relates to wandering monsters, and opening stuck doors is important because it uses up time in the dungeon which blah blah blah
anyway, that may all be true but I just don't want to deal with all this movement rate bullshit or even drawing maps for the most part. And I know my players find it tedious to draw maps from my descriptions, so why would I bother?
So I got to thinking that you could reverse engineer the risk/reward system of wandering monsters and then simplify it so it doesn't depend on precisely measuring the party's movement through the dungeon. Or on stuck doors, which are the most boring goddamn thing to waste your gaming time on. Or on stupid rules that nobody even remembers like how in LL and OSRIC you're supposed rest for one turn in every six.
Basically the rules are so complicated and varied depending on the specific retroclone and the predilections of the DM that it's impossible to crunch the numbers on how often they are 'supposed' to turn up a wandering monster. Instead, it's easier to just put it in the hands of the individual DM, which makes sense because some DMs will run relatively small dungeons where every room is stocked with important stuff, while others will do big dungeons where half the rooms are empty.
So here's how I want to do dungeons for my face-to-face group in the future:
1. Instead of grid mapping, just draw rooms as nodes with lines connecting them for corridors. A long corridor can be a node, and a large room can contain multiple nodes.
2. Assume that the PCs are mapping even if the players aren't. None of this "you drew the map wrong, so you get lost" bullshit. On the other hand, if the PCs are fleeing for their lives they don't get the privilege of full map directions.
3. A wandering monster check is triggered every time the party moves from one node to another.
4. Other things that also trigger a wandering monster check:
- making loud noises or doing other things that attract monsters directly
- searching a room
- other time-consuming activities (excavating a hole, fiddling with a puzzle, etc.)
- trying to open a stuck door, if you must insist on having stuck doors in your game
5. This means that wandering monster checks are significantly more frequent than in B/X or AD&D. To offset this, they are rolled on a D10 by default. To increase or decrease the frequency of monsters, simply change the die size for the dungeon.
6. If the party is heavily encumbered, reduce the encounter die size by one step.
Why a D10? Well, by my calculations one room takes roughly 2 turns to explore, including the time for resting, stuck doors, and other fiddly little rules. If you check for monsters once every 3 turns, then 2 turns = 2/3 of a check. A check is 1/6 of an encounter, so a room is worth 2/3 * 1/6 = 2/18 = 1/9, so close enough to 1/10 (not totally sure about this math, I did drop out after 10th grade.)
The advantages of this system are:
- It's simple.
- It's transparent to the DM. I know that the players will encounter a monster in 1 out of 10 rooms, not accounting for their other time-consuming activities.
- It's transparent to the players. They'll see me rolling my D10 and know exactly when they're drawing heat. The options they have that trigger a roll, such as searching, are all strategic tradeoffs and not just busywork.
- It's abstract. You can convert "rolls made" to "time spent in the dungeon" if you really need to know how long the PCs have been there, but generally it's a more nebulous measure of "how much danger are you in".
The disadvantages are:
- you don't get the tactile, objective feeling of actually drawing a map
- you don't get the detailed tactical tradeoff of encumbrance vs. movement speed, but it's still there in some form in point #6.
- It doesn't give you a precise measure of how much time has been spent in the dungeon. This means you can't have the players run out of torches/lantern oil, but that never happens anyway.