Recently, there was a comment on JB's excellent B/X Blackrazor blog by Simulated Knave claiming that they found 1E AD&D lacked solid advice for interaction with NPCs outside of combat or for worldbuilding, something that the commenter found that 3E D&D/Pathfinder was better at.
Now, I've played a bit of PF but it has been many years since, and I never had the books. I've only briefly looked at the PF 2E thing. So maybe the good folks at Paizo went above and beyond with advice for NPC interaction and worldbuilding. But I did play plenty of 3E/3.5 D&D, and I have those books on PDF still to reference.
WAY back, I did also make this post about how OD&D has more pages of rules for exploration of the game world than for combat within the game system. The sixth post I ever made here. I think that's relevant to the discussion as a bit of context.
Let's examine Simulated Knave's claim.
Of course, SK, if you're reading this, feel free to comment and let me know if I misunderstood your intent or points you brought up. It's always possible, and I'm open to having my mind changed on this front.
Also, one last disclaimer. As most regular readers know, I'm a Frank Mentzer edited BECMI kid. That's my go-to D&D set. And Frank did a pretty good job (I feel) giving the budding DM advice on how to build the dungeon, how to build the home town, how to build the world, and how to set up the politics, and how to set up the planes of existence/powers that be/legendary artifacts* of the world all in an easily digestible format that provides just enough advice to get you going on each of these fronts without overwhelming.
*Having only relatively recently acquired the Immortals Set, and still not having read and digested it thoroughly, I do have to admit that a bit more advice on creating planar adventures could be helpful than what's in the Companion and Masters Sets.
But the claim by Simulated Knave was about AD&D giving "garbage" advice compared to d20 system games.
So let's start with d20.
3E etc. obviously have some simple and direct player facing rules for NPC interactions. There are skills for lying to NPCs, sweet talking with NPCs, trying to see if the NPC is lying to you, and so on. Bluff, Intimidate, Diplomacy, Sense Motive, Perform...are there anymore? Maybe I'm missing one or two. Roll d20+skill bonuses vs a set DC or the NPC's contested roll.
Sure, it's simple, it's easy to remember, it's in the PHB so players can know the rules. But it doesn't always make sense. I don't care that you've got a +15 bonus to Intimidate, your Barbarian with the +5 greataxe is not going to make the Lich Lord, who commands the army of the dead outside the gate, tremble in his boots. I don't care what you say, or that you rolled a natural 20. Maybe try again after his army has been decimated and you've located his last phylactery. Then you might have a chance.
And yes, I know that d20 has advice to not allow a roll in that sort of situation, but I've seen plenty of players demand things like that over the years.
What advice or rules does the 3E DMG (I found my 3.0 DMG before the 3.5 one, so I'm referencing that) have for interactions with NPCs outside of combat?
Two pages on using the Leadership feat to manage sidekicks and cohorts for PCs, including a half page sidebar on animal companions.
Then we've got a bunch of pages on NPC stat blocks (mostly combat stats). And a big section going over all of the combat rules, procedures, and so on. It's 25 pages long.
Then there are a few pages on dealing with environmental dangers, which counts as world building advice.
The next section is on skill and ability checks, so we get detailed rules on how each skill can be used, and example difficulties for them. This includes the various skills for NPC interaction mentioned above, of course. It's a little over 4 pages. Then we're on to saving throws and adjudicating magic. The second part could be considered world building advice.
Now we get into the dungeon, wilderness, adventure and campaign creation advice. And it covers around 60 pages for all that. But with in that, it's not all world building advice. A lot of it is combat encounter creation advice. Or how to mechanically handle traps. Or dungeon dressing suggestions. Encounter tables. Random town generation. Advice on linking adventures and player goals into a coherent campaign. Not bad stuff, but a lot of it reads as very surface level to me. There are world building tidbits in there, but also a lot of combat encounter (or challenges requiring skill checks) explained, more so than there is advice on crafting a fantasy world. There is world building advice, as I say, but I don't find it as deep as SK seems to. Or maybe the 3.5 DMG or Pathfinder improved on this base.
There is a section in all of this on running NPCs. Or rather, there's some advice on the stock types of NPCs you might include in an adventure or campaign, and advice on how to use them as allies or opponents. There are some rules for DCs to influence NPC attitudes. Some hirelings you could hire explained.
After all this, there's the XP and treasure sections, some reference charts, and the index.
So for NPC interaction, SK claims that 3E/PF provide the following: "What are the odds of sneaking past an NPC? Of stealing from them? Of convincing them of something? Of them knowing some particular fact? Of them existing at all in the particular town?"
3E does do these things. But AD&D gives you all of that, as well. It's different. Instead of giving you the NPC's Perception skill for the player to roll their Stealth score against, AD&D gives you the surprise round and the Thief skills for hiding and moving silently. AD&D has NPC reaction tables. In fact, they're more robust than 3E's. It's got modifiers for racial animosity, for example, in addition to general reaction rolls. How do you decide in AD&D that a particular NPC lives in a particular community or knows a certain thing? Well, that's called making a decision on your own, rather than rolling some dice.
All of the NPC interaction that SK seems to laud in d20 systems is just a very mechanical functional take on interaction. d20 gives you lots of skills and difficulty numbers to beat, while AD&D gives you actual advice on crafting a medieval fantasy world (granted, a very specifically Gygaxian one) and lets you extrapolate from there how you want your NPCs to interact with the PCs.
As for world building, I mentioned above that d20 gives you lots of lists of challenge ratings (how hard is it to climb a wooden wall vs a stone one, or how hard is it to pick that lock vs the lock over there), and a lot of surface level dungeon/world dressing. But everything is centered around making some sort of skill roll, saving throw, ability check, or...yes...combat. There's not a lot of fodder for interesting world building and organic, dialogic play.
AD&D's 1E DMG has tons of pages of charts, lists, and what not to give flavor to the world. It's got lists of gemstones and flowers and their folk belief uses. It's got that random harlot table.
There are 9 and a half pages near the front of the 1E DMG giving advice on NPC hirelings, retainers, specialists, and so on. Way more detail than 3.0. And yes, much of this is also mechanical. Will your spy complete their mission? How long will it take the sage to research your questions? How will the dwarven mercenary crew react to your Elf trying to hire them? But it's also a lot of extra information on running these NPCs as well.
Anyway, I'm out of time so I can't dig for more examples right now. But they're there.
Yes, there are a lot of combat rules in AD&D. There are a lot in 3E. But in my opinion, AD&D gives richer information on all of these things. Sure, it lacks really detailed stronghold development rules. But BECMI has them, so it was never a problem for me. Maybe that's a cop out, but it's true that a lot of gamers I know mixed and matched what they liked from the TSR editions to fill the gaps.