Were players really denied the rules by moving them to the DMG? I know every one of the players in my 1e days owned or read the MM and the DMG regularly. We had the rule that you couldn't open the MM at the table, but we all knew all the rules.
In our early days of play Storm I was the only one who owned any of the books (it was a long time ago). I gave my players the Player's Handbook to allow them to read and to create characters.
Later on they bought their own PHs, DMGs, and MMs, so that they could start DMing for themselves.
At that point I started doing something I've done ever since. They never encountered a monster or a magic item or anything of real importance that was exactly like it occurred in the books. And I think that is the solution to this game dilemma. Or one of the important ones. (Of course I'm not discussing rules so much as information exchange.)
Yes, a Paladin might get a Holy Avenger, but the Holy Avenger in the DMG was never the Holy Avenger they got. The Holy avenger in the DMG was a basic design Template to me, what they got instead was a Holy Avenger specifically geared towards the setting, the character who was to receive it, and which had some of the same basic functions as the "standardized Holy Avenger" in the books, but with entirely different functions and abilities as well. And they did not automatically know how to use the various functions the sword had merely because they possessed it. They had to figure it out, to decipher what the item could do by experimentation as they went along, to figure what the exact abilities were and how to employ them.
The same for monsters. Encountering a Troll was something vaguely like the Monster Manual Troll, but the Troll in my world was also different from the "standardized Troll." They could never be sure what they would get exactly, and many monsters were entirely unique. Monsters, like NPCs, which I also kept tight informational control over, also rarely fought to the death unless trapped or cornered, and so they were not automatically disposable and expendable, given them potential long term lethality. Then again the corpses of many monsters, as with many mythic monsters, were often very, very valuable. Bodily fluids and scales and eyes and other things could be used to create things or enchant things. In this way monsters were both a real and ongoing danger to the world at large and often a valuable commodity to the player, both dead and alive (some monsters were only useful if alive, such as a monster that produced a certain type of venom that could be used as a medicine against disease, or to produce a counteractive agnate to being mortified by another monster - i.e.
the bacteria that can kill the virus). Monsters were sometimes also benign or even helpful, especially compared to reputations, and so the players had to figure out if a monster was really what it appeared or was reputed to be. Magic was often as likewise unpredictable, complicated, and dangerous as monsters.
Yes, this meant more prep work, but over time you develop procedures and tricks and systems for making those kinds of things easy to modify and set-up. In any case by making the different interactive elements of the world (magic items, relics, artifacts, NPCs, monsters, and magic, etc.) unpredictable and non-standardized, different than being merely "by the book," I've been told numerous times over the years that my setting is far more interesting and dangerous and unpredictable and fun than having monsters and magic and items that are well-known and easily predictable. (I've also found that when it comes to NPCs, monsters, magic, and magic items,
don't let those things become predictable in behavior any more than they should be predictable in function.)
And I think that is the point. In order to truly surprise and challenge your players you can't operate "
by the book," especially nowadays when information is so easy to gain and disseminate. The one thing the DM can keep truly secret is his world, how it operates, who and what populates it, how magic works, what the true motivations of the NPCs are, and so forth.
If you're going to operate by the book, and everyone has access to the same information, then you cannot possibly expect to surprise or even challenge your players (short of the idea of
"un or im-balance") because everything in that world or setting is already known. There is nothing to migrate across the screen because there is, in practical effect, no screen at all, there is no information selectivity, there is no information discrimination, there is no information security,
and therefore there are no secrets and no surprises. The only real thing that separates the DM from the player as far as knowledge and information base is chair position.
And that distinction is merely decorative.
That's all very modern and democratic. There is however nothing at all similar to anything resembling
"fantasy" in the idea, nothing fantastic in the way that works, and unless the players
"role-play" merely with the singular intention to
"win every fight" then I can't imagine that information equality means anything but eventual boredom for the players, and the DM.
If your world is uninteresting and unengaging, not unique, and is already well explored (that is to say, if all of the information about it has already spilled like disemboweled guts "from the books,") then no wonder the game needs a new edition every few years. The new edition, the new rules and ways of doing things stand in as a substitute for the feeling of wonder and of the unknown that is supposed to be a necessary component of most any fantasy world.
But when you set up a game and a fantasy world in which it is possible to know everything merely by reading the books, then what is the real point of exploration and adventure? You already know exactly what you will encounter. The only real question then is not what will I possibly encounter in this world, but when will I encounter what I already know is coming? And that isn't fantasy at all, that isn't a Golden Thread or a Yellow Brick Road towards danger, excitement, and the unknown, it's just a well-trodden paper trail to a relatively safe place you've already visited numerous times before.