Hard cap the number of modifiers in a single value

[TavishArtair]

A general rule I have learned from playing way too much fucking D&D 3e, and then turning around and playing Weapons of the Gods.

Hard cap the number of modifiers. Find a way that works. "Use highest" is a good one. Highest bonus, highest penalty. Or just highest value period. If you want to double the complexity of the system you can make there be "named" modifiers of a type that can then be referenced and you can add a modifier to that type of modifier. Using the highest bonus, the highest penalty, and having a single type of named modifier seriously allows there to be up to four variables going into a single roll, plus your base dice value, which can be determined by what the fuck ever, and itself can constitute a fifth value.

Even with this simple rule, we have run up against the lower limit of variables the human mind can track (7+/-2 means we get 5 to 9). This means we should stop here, unless we seriously want to make the game as hard as taking a math test. And for some people, it still will be. Seriously, don't do what D&D did. AC bonus doesn't need Dexterity, dodge, armor, enhancement to armor, natural armor, and enhancement to natural armor to be the STARTING point for determining most AC scores, nevermind deflection and sacred and morale and bullshit bonuses...

[Juton]

Out of the box this screws over PCs. Monsters are designed by lazy developers, so they'll just give the Dragon +30 natural armour and move on to the next monster. When players are stacking all those modifiers they're not putting the monster's attacks off the RNG, they'll putting it on to the RNG.

If you want something like this to work you'll need a big chart of what's the proper AC at this level, the proper saves etc., then the players get to add this bonus. If you do this for attack modifiers and save DCs then you're going to be making 3.5 very bland, which isn't a good design goal.

[Judging__Eagle]

Half all Monster Bonuses, Hit Points, and Damage roll totals on creatures CR 10 and up.

Bang!

[TavishArtair]

Out of the box this screws over PCs. Monsters are designed by lazy developers, so they'll just give the Dragon +30 natural armour and move on to the next monster. When players are stacking all those modifiers they're not putting the monster's attacks off the RNG, they'll putting it on to the RNG.

If you want something like this to work you'll need a big chart of what's the proper AC at this level, the proper saves etc., then the players get to add this bonus. If you do this for attack modifiers and save DCs then you're going to be making 3.5 very bland, which isn't a good design goal.

It has nothing to do with whether the stacking modifiers are "too much" in terms of absolute values they're creating. It is too much in terms of objects you are tracking. Moreover, rules like this need to be implemented on a first-principles basis. You would have to gut the entire 3.5 system for it to work.

I have no interest nor suggestions for implementing this kind of rule in 3.5 D&D, because 3.5 D&D is already an irretrievable pile of crap in these terms.

You're also forgetting that D&D monsters already get to buff themselves up already anyways because all of the dangerous ones are caster-type mobs themselves or are supported by one. This results in what approaches a zero-sum game for most generic buffs that are easily rolled out by either side. The only reason you don't see these is because the D&D is.... fancy that... too lazy to track all these modifiers.