How would these house rules affect D20?

[Quartz]

Well in 3.5 having multiple prestige classes per PC is the "norm" and then you have to adapt for the NPCs too.

I really don't think that this is a problem.

But in attempting to stay with the design model - WotC most often used skill ranks to determine the minimum level possible.

Max ranks for a "trained" skill was class level +3 for an "untrained" skill it was 1/2 of that.

Now using your method - how would you account for this without having skill monkey classes being able to enter marital oriented prestige classes (with skill rank prerequisites) much earlier than marital classes?

Well, generally, one gets down on bended knee and offers the lady a ring.

I'm a firm believer in Prestige Classes being appropriate for the setting and no allowing just any Prestige Class willy-nilly. Each adaptation should be campaign-specific.

Requiring feats for "trained" skills makes things a lot more complicated.

You would need to add to the number of feats a character gets for each "class". That is "skill monkey" classes (rogue and bard) would require a lot of extra feats.

I've been thinking about that and there's an elegant solution: make being better than semi-skilled a class feature. Say a +1 class bonus to untrained skills per n levels. And give everyone bonus feats on odd levels, instead of every 3 levels.

Historically even minor "tweaks" in the rules have invariably caused a cascading effect of more and more house rules to compensate. This is something I have seen and truely believe that most people who have delved into any sort of subtantial house-rules have also noticed.

This is the whole point of asking first!

 

[Quartz]

So you're weakening players, without weakening monsters, with this one. This is a recipe for accidentally misjudging encounters.

A very good point. I don't think it applies to monsters from the original Monster Manual, but rather to those from the subsequent ones after Bonus Inflation set in. But I go for heavy multi-classing anyway so I'm used to tweaking the ECL.