One of the things I’ve taken to over the past couple of years is just plain setting (either by die roll or by decision) the number of creatures encountered regardless of which characters have (or might) encounter them. For instance, if I decide or roll a goblin tribe has 37 members, one of them a 3HD chief and 2 of them 2HD champions, then that tribe has 37 members whether it’s encountered by a party of six mid-level adventurers or by one low-level fighter. This seems to fit in well with the current takes on the “sandbox” approach to gaming which, itself, seems to be much closer to how the game was intended to be played way way back in the mists of the early days.
I was surprised, therefore, to find out about this tidbit in OD&D’s Book 3: The Underworld & Wilderness Adventures (page 11):
If the level beneath the surface roughly corresponds with the level of the monster then the number of monsters will be based on a single creature, modified by type (that is Orcs and the like will be in groups) and the number of adventurers in the party. A party of from 1–3 would draw the basic number of monsters, 4–6 would bring about twice as many, and so on.
I think I believe that a definite number of creatures, regardless of party size or strength, is the way to go, and that if the party is overmatched they had better get out of Dodge in a hurry.
It’s not that I’m overly troubled by seeing this, or that it makes me question my method just because it was in the original books, but I am surprised to see it.