I'd much prefer a completely new approach for the core rules. Rather than break the PHB/DMG/MM or one massive tome with everything crammed into it, I'd like to see the books broken down into what purpose they serve.
Book 1: Player's Handbook. This contains the rules for character creation, the races/classes/backgrounds/themes, a spell list, and a list of the sort of items a character can expect to buy (mundane weapons and armor, equipment, low-level magic consumables (potions, alchemist fire, thunderstone, etc.) Include the rules for various modules that would be needed for creating a character using those modules.
Book 2: Rules Compendium. All the rules for attribute checks/contests, combat, spellcasting, etc. This book should contain just the rules and nothing else.
Book 3: Dungeonmaster's Guide. Contains advice for how to run a game, write an adventure, create a map, make NPCs/custom monsters, and things like that. Includes tables for randomly generating villages, NPCs (including names), and things like that.
Book 4: Dungeoneer's Handbook. This book contains all the magic items, treasure, traps, and monsters you would put in a dungeon. Includes lots of tables for randomly generating dungeons, placing treasure, etc.
The reason I want the books divided this way is so that each book serves a specific purpose and doesn't waste space when it's not needed. I don't need the character creation rules on the table during the middle of play, and that's 1/4 to 1/2 of the PHB for 3.x/4e. I don't need the lists of magic items and monsters when I'm not writing an adventure. I don't need the entire spell list when I'm trying to look up what combat modifiers apply when fighting underwater.
I'd prefer this format because I've wasted too many hours of my life collectively thumbing through rulebooks going past things that are completely irrelevant to the task at hand trying to find some rule or item or spell or whatever, both during a game session and during prep. I've also gotten sick of the wear and tear on my books getting constantly passed around the table and thumbed through (especially true of my old 2nd and 3rd edition Shadowrun books which literally fell apart) plus the arm strain with the 575 page tome that is the Pathfinder Core Rulebook because different players need to look up different things. That's on top of the frustration of having to snatch the book from the sorcerer who was looking up a spell for his next turn because I needed to look up some rule on a skill that no one ever uses except the one time the sorcerer was actually deciding what to do before he came up in initiative.
I also don't want one massive core book because then I would be the only person to buy it, which is my problem with Pathfinder. If I were running a 4e game, it would be easy to convince one or two of the players to pick up a copy of the Rules Compendium so there'd be extra copies at the table since it's under $20. Trying to get them to do the same for the $50 Pathfinder book is like pulling teeth, especially since they all have smartphones to look up the PRD (which just gets them further distracted by their phones playing Angry Birds or Words with Friends or just texting when we're in the middle of the combat and it's not their turn).
The split I stated above was intended so that each book has a clearly defined purpose. One book for character creation that would be rarely referenced during gameplay except by the caster looking up spell descriptions or when they go shopping in town. One book to help out new DMs on how to run a game. One book used solely during game prep for the DM to populate the adventure with monsters, NPCs, traps, and treasure. And one book that is referenced frequently during the game anytime a rules question comes up.
The names I had to fiddle with to get the traditional book names, but I'd really like to see something like this for the core books. Split them up based on how the books are used, not just who uses them. And if they're printed in a digest format at a low pricepoint each, there's a good chance there might just be two or three copies floating around the game session to cut down on the time waiting to look something up.
)... as a player I only need the PHB.
