Parent Classes: Each one of the following classes lists two classes that it draws upon to form the basis of its theme. While a character can multiclass with these parent classes, this usually results in redundant abilities. Such abilities don't stack unless specified.
So, I'm sure we're all familiar with this line from the Advanced Class Guide.
I've seen it claimed by a few people on the forum that a multiclass gunslinger/swashbuckler wouldn't benefit from both Nimble dodge bonuses because of this line.
But, is that true? The 'abilities don't stack' only calls out redundant abilities.
Dodge bonuses stack, so getting two doesn't make either of them redundant.
In the same vein, I've seen it claimed that a multiclass rogue/slayer wouldn't get the sneak attack from both, but since sneak attack is just 'add some dice to damage', and there's already a ruling that sneak attack from multiple classes stacks, would either actually be redundant and thus covered by this?
And how about spellcasting for an arcanist/wizard?