The 3.X DMG says that you should warn your players if you are using only status quo encounters (good advice) and that good adventure design uses the CR guidelines (meh advice, IMHO).
In a "best reading" of the 3.X DMG, the Status Quo design would be considered "setting design" rather than "adventure design" so that the second statement wouldn't effectively call Status Quo design bad design. However, this is by no means explicit.
The 1e DMG calls for a rough balance based upon location, as well as what makes sense in a given location, to create encounters.
Players can (and do) learn the CRs of monsters, and can (and do) use these to make informed decisions, just as 1e players learned the abilities of (at least commonly encountered) monsters. This is one of the reasons that new monsters were so common in older modules, and why the ability to quickly and easily generate new monsters is (IMHO) important to the game. 3.X uses monster advancement and templates to do the same thing, and I certainly think that monster advancement and templates are useful (if sometimes combersome) tools in this regard. The
Lost Caverns had so many new monsters that they needed (unless my memory altogether fails me) a seperate booklet.
However, if one's thesis is
I've seen numerous references to a supposedly commonly known "fact" of AD&D1 -- that dungeons were more dangerous, not balanced (appropriate) for the levels, etc. (especially compared to D&D3).....The advice and charts in the D&D3 DMG are very similar in tone and function to their AD&D1 DMG counterparts.
then, yes, I do think that a rougher approximation of the challenge that a monster represents (i.e., Monster Level system) leads to a wider range of challenges, and hence a more dangerous dungeon, than one in which the level of challenge is more precisely known.
But you don't have to take my word for it. All you have to do is determine what the various CRs would be for an "adventure" of any given level using the CR system as presented in the DMG (roll randomly where there is a choice), then create a random dungeon using the 1e DMG based upon the level you believe appropriate for the same level characters. I recommend 1st level, if only because we know that 1st level PCs are imagined to be able to handle many of the challenges of a 1st level dungeon.
Then compare the two, and see which has the higher potential for lethality, as well as which has the wider range of potential challenges. Don't forget, of course, that your 1e dungeon might pitch you into a lower level without you knowledge and/or conscent, whereas if you follow the CR guidelines, even if this happens it will not affect the level of challenge that you face. Rather like that 1st level party in the Caves of Chaos coming face-to-face with a minotaur, owlbear, and three grey oozes in short order.
This is the sort of analysis that I imagine Quasqueton would be quite good at, and I look forward to seeing the results. Perhaps it might help to explain why some believe that trying to make the guidelines more direct, precise, and clear is in some cases a bad thing.
RC