Rule variations between PF1/3.5 - Stacking

[Kurald Galain]

So; For many years I played specifically 3.5. Eventually mixing PF1 in. As MOST things appear to be the same with few variations. Besides some obv class changes. Were any base rules that I am unaware of changed going from 3.5 to PF on how typings stack. ??

Yes, it is a rule in PF that you can't add the same ability to a roll twice, unless they have different types.

Nymph gets a deflection bonus, Scaled Fist gets an untyped bonus, so they stack.
On the other hand, Oracle (Nature or Lore) gets an untyped bonus, Scaled Fist gets an untyped bonus, so they don't stack.