mamba
Legend
went to the 1e DMG to look for those rulesWell, 1e has very extensive and elaborate treasure tables, and every monster is described as having specific types. Now, exactly what a specific given monster in a specific place has, yes that is up to the DM. Could a DM simply refuse to place adequate treasure? Sure!
and that kinda is where it ends. There is a table of random traps, but that is not by dungeon level and the advice about treasure is relatively generic.
First of all, not all monsters you encounter have their treasure according to their treasure table.
"All monsters would not and should not possess treasure! The TREASURE TYPES given in the MONSTER MANUAL are the optimums and are meant to consider the maximum number of creatures guarding them. Many of the
monsters shown as possessing some form of wealth are quite unlikely to have any at all."
They do get more treasure deeper down in the dungeon but specifics are pretty nonexistent (apart from the treasure type per monster part)
"In more inaccessible regions there will be stronger monsters — whether due to numbers or individual prowess is immaterial. These creatures will have more treasure, at least those with any at all. Copper will give way to silver, silver to electrum, electrum to gold."
and just to not make it too easy on the players
"Rather than stocking a treasure which the victorious player characters can easily gather and carry to the surface, you maximize the challenge by making it one which ogres would naturally accrue in the process of their raiding. There are many copper and silver coins in a large, locked iron chest. There are pewter vessels worth a fair number of silver pieces. An inlaid wooden coffer, worth 100 gold pieces alone, holds a finely wrought silver necklace worth an incredible 350 gold pieces! Food and other provisions scattered about amount to another hundred or so gold nobles value, and one of the ogres wears a badly tanned fur cape which will fetch 50 gold pieces nonetheless."
and the list goes on
Magic items are also handled rather imprecise
"As the campaign grows and deeper dungeons are developed, you exercise the same care in placement of selected and balanced magic items. Of course, at lower levels of the dungeon you have more powerful single items or groupings of disparate items, but they are commensurate with the challenge and ability of participants. Guardians tend to employ the items routinely, and others are hidden ingeniously to escape detection."
So yeah, a lot of DM fiat and some rough guidelines. Certainly nothing that really restrains the DM and puts the players in control, allowing them real risk vs reward decisions, apart from 'the deeper, the more of both risk and reward'
to a degree, yes, no different from how the game works outside the dungeon as well. In both cases the DM placed level appropriate monsters and rewards in level appropriate environmentsHonestly, the absolute size of treasure hordes is not even really the point. The point is that the players are the ones defining the level of risk they take, and reaping the reward appropriate to that. If a given GM makes treasures 1/10th as big as another, there's still the same proportionality there. It may change the character of the game in various ways, but it isn't a part of the question of who is in control of risk management, that's the players.