In 3.X and PF1 I added more armor.
Armor is made for protection on the battlefield. D&D assumes a magical world, which means any kingdom worth its salt is going to try to develop armor that slightly counters magic.
I added in armors that could only be worn by Paladins and Fighters, requiring the Super Heavy Armor Feat, which Fighters and Paladins got for free.
It had better AC, gave them a DR, and, of course, bonuses to deflecting spells.
Then I added exotic metals and stuff like "dwarven alchemical steel" and stuff like that.
Of course, I'd also limited magic users by 'max spells per level in traveling spellbook' as well as a few other things.
One thing I did that had some players walk away, is that different classes moved up on the PF1 leveling chart different. Casters were largely on the "slow progression" XP chart.
One more thing I did, just to see how everyone took it, was I included the old 1E/2E "Max Class Level by Race for PC's" which stopped a lot of the faggy "half drow half dragon half elf half dwarf half vampire" stupid shit I saw, since your max class level by race was determined by the lowest race rather than the top. You could go up for exceptional stats (by your primary stat bonus) in levels to get past the cap, but that was it.
Another nasty thing was laying down another rule chunk from 1E.
Non-martial characters could get a maximum hit die of 10. For casters 11th level would be 10+1hp, where for non-caster non-martials it was 10+2 hp.
Con bonuses for non-martials tapped out at +2 unless the racial bonuses were +2 or +4, then it tapped out at +3/+4 respectively.
Martials (and rogues) were the ONLY ones who got more than 1 attack, and I dropped it to +3/+1 for martials (extra attack every other round till +5, then scaled up), +5/+1 for rogue style. Wizards and casters were shit out of luck.
I also added casting time where casters had to proclaim
at the start of the round what they were casting and until 7th level had to proclaim
their target creature or area at the beginning of the round. (Improved Initiative for casters became suddenly important) Their init turn was what they would normally get PLUS the level of the spell. They were casting from the beginning of the round till their modified initiative and could only take a single 5-foot step if it had a somatic component. If they got hit, it was a concentration check.
I also added back in opposing schools of magic.
The last thing I always did was I flat out let them know "No, you don't get to pick a random spell out of the book when you level up and have your character pull it out of their ass." That got some screaming, but fuck those people, they can find a different game.
Lastly, I reintroduced "training", which meant time spent (3 days per level, 1,000 gp per level) and made guild and fraternal/sorority membership suddenly a huge deal, since it could reduce the cost and training time.
It's amazing how much the game changes when power has a cost.
And as we saw with the pigfarmers argument a while back, old school players hate the idea of heroic anything. Every adventure had better have a >60% mortality rate or you're playing it wrong.
What's funny, is with all the limitations I put in, all the adjustments I did...
...those same faggots called me a power gamer because I let the players be heroic even with all the adjustments to 3.X.
"They should all start as dirt farmers with no teeth and enjoy fucking pigs! Because that's how the medieval world is!"
I had cool backgrounds and shit, because I always assumed the PC's had a certain 'spark' that NPC's didn't that let them rise in power so quickly.
I also had some of those old grognards try to tell me back in the early 2000's that having a celebration for the party members at a small town they saved every year was stupid and dumb.
Then ENWorld did a poll and most of those grognards who insist everyone start as Dugger the Shit Digger had either never actually played D&D or hadn't played in years. Those that did play admitted they had a problem keeping players.
I know, flat out, that I could promise everyone I was going to slap the above shit down on a PF1 campaign, with limiting the classes and races to the Core Book Only until we got used to each other and we learned each others gaming habits, with a stat block of 16, 15, 14, 13, 12, 10 and 3 points to move around, announce there will be a mixture of dungeon crawl, hex crawl, exploration, urban adventures, and role playing, they'll want to take notes. I could say there's going to be slavery, racism, nationalism, sexism, and even different sub-races racism, then tell them that the world has suffered the collapse of the Great Empires only 50 years ago and the whole world is still grinding down into a Dark Age...
And I'd have plenty of people who wanted in.
Especially when I say some shit like "And the Gods have decided that the mortals can change the fate of their world. That means you, the players, can stave off the Dark Age with your PC's."
People like
a challenge and this whole shit of turning characters into big gray blobs where the player is the biggest and the grayist and the blobbiest and all conflict is thinly veiled progressive bullshit with no real conflict fucking pisses me off.