Dungeon Encounter Proportions (And Crab Knights)

Oh boy its rambling theory crafting time yet again here in the Bogeyman's Cave! I'm gonna be comparing the general proportions of empty rooms, traps, monsters, and special rooms in dungeons by edition of D&D.

Now, Original D&D has a very simplistic suggestion of rolling a d6 for each room and space, with a 1 or 2 showing that a monster is there, 3 to 6 showing that there is no monster. There is no consideration for traps or "tricks" as OD&D called special rooms. This crude system gives us the proportions of 33% monster encounters and 66% empty rooms (or at least, rooms without monsters).

As near as I can tell, Holmes Basic D&D didn't have any guidelines as to Dungeon encounter proportions, instead just allowing DMs to wing it using the included dungeon geomorphs and monster and treasure assortment. 

AD&D had a rather complex random dungeon generation system, with a bunch of tables to fool around with. However, I'm gonna be focusing on TABLE V. F.: CHAMBER OR ROOM CONTENTS. Instead of a d6 roll to determine room contents, one rolls a d20, with 1-12 indicating that a room was empty, 13-14 indicating a monster, 15-17 indicating a monster with treasure, 18 indicating a special room, 19 indicating a trick/trap, and 20 indicating just treasure. This gives us a 65% chance of an empty room, 25% chance of monsters, and a 10% chance of tricks/traps/specials. 

The Moldvay Basic Set returns to a d6 based system, albeit more complex than OD&D's with 1-2 representing monsters, 3 representing a trap, 4 representing a special room, and 5-6 representing an empty room. This gives us the proportions of 33% monsters, 33% empty, 16% traps, and 16% special.

I'm not sure if BECMI has a different system, but I do know that the D&D rules Cylopedia uses the same generation system as B/X, and as near as I can tell AD&D 2e doesn't even have random dungeon generation rules (at least not in any of the core rulebooks).

Here are the proportions as shown side by side for easy comparison.

Room Type	OD&D	AD&D	Basic D&D
Empty	66%	65%	33%
Combat	33%	25%	33%
Trap	n/a	5%	16%
Special	n/a	5%	16%

Now which one of these systems is best? Is it a good idea at all to randomly stock dungeons in this way, or should one simply use them as guidelines? Does it even matter?

I've always been a big proponent of using the guidelines of "For every 10 rooms, have 3 empty rooms, 3 combat encounters, 2 traps, a special room, and a room with an NPC to interact with". And for the most part, I do think that this system holds up, hell, the game I'm currently running has had every adventure thus far use those proportions, and its going smoothly.

But its important to note that the designers of these games didn't seem to care that much about encounter proportions. Take a look at any module by Gygax and you'll quickly see that he clearly didn't have just 5% traps and 25% monsters. 

Its most likely that these random generation systems are meant as training wheels for novice game masters, a tool to use to help start things out but not rigid laws to follow.

Anyway to pay the Joesky Tax here are stats for crab knights

Source unknown, please let me know if you know the artist

Crab Knights

# Appearing: 1d3
Hit Dice: 3

Armor Class: 17 (as platemail+shield)

Movement: slow
Attacks: 1 sword (1d6+1), 1 claw (1d6)

Special: Crab Knights can only move sideways, in order to change direction they must spend their movement action to turn. 1 in 6 crab knights have magic powers (roll randomly for a spell known).

Once errant knights on a quest to slay a vile water dragon, the Crab Knights were cursed by a sea hag to become creatures of the deep. They can spend short amounts of time on land, but inevitably must return to the sea. They are driven by a fierce longing to be human again, and become violently jealous upon seeing human beings, flying into a murderous rage. Crab Knights can be broken free of this rage by being shown the heraldry of their old knightly order, which restores them to rationality for a time.