Do Cavalier archetype modifications to Challenge replace or stack with basic damage of Challenge?

[Trollboy]

Basically, as listed above and do we have an official clarification on this? My GM is of the opinion that my challenge modifier completely replaces the core Challenge mechanic. And he might be right but I've failed at my forum search-cu to find anything indicating this.

Thank you all for you help in advance!

[Java Man]

It would depend on the wording used in the specific archetype, is there one in specific you are looking at?

[Trollboy]

Yes, the Honor Guard archetype to be specific, thank you for the response!

[nicholas storm]

It modifies challenge so that in addition to the regular challenge bonus (+1 damage per level), you get -1AC and your ward gets +1AC.

[Trollboy]

That's the contended rule point I'm having with my GM, do we have any rules quote from either the books or an errata that specifies that it stack instead of replaces?

[nicholas storm]

The last sentence in Sworn Defense says "This modifies the challenge ability." If they meant to replace the challenge ability, it would have said that.

[Trollboy]

If only that were enough in this circumstance. Thank you for at least validating my read on the rules. I'll try to discuss it with my GM, thank you for your Time!

[Cavall]

Your read is correct. It modifies it to do more, not replaces it.

[nicholas storm]

One thing you can tell your GM is that archetypes are supposed to trade out abilities at roughly the same power.

By his point of view, you would be trading away challenge (one of the more powerful abilities in the game) for basically nothing. Sworn defense gives someone a +1AC and you a -1AC; basically a net value of 0.