How do multiple crests interact?

Question

I've started a playthrough on new game + and want to theorycraft and min-max. I was wondering how the interaction of multiple crests work. For example if I put the mystery crest from Marianne (Maurice crest) which seems very similar to Fraldarius crest (Felix's crest) . They both "Sometimes raises Mt when using a weapon", would they both function independently or can they "stack" on a single hit?

Otherwise similarly can the Fraldarius Crest stack with say the Charon/Gautier or other similar crests when using a combat art?

Can a raise Mt when using weapon crest stack with an Indech Crest which allows for double hits?

Answer 1

The reddit community has been play testing with how crests with in Three Houses. They are still formulating how crests work when multiple are equipped, but the following information is what has been observed:

Whether it be an inherited or equipped crest, each crest works independently from one another and only one can activate per action. So in your example with the Fraldarius and Indech crests, it would not be possible to do a double hit with increased might. However, if you were to have Charon and the Gautier crests, while it would not increase your might twice, it would increase your overall chances of having an increased might on that action since you have multiple crests that provide the same effect.

On each action, crests are checked in the order of priority. The inherited crest, if any, takes the first priority and then it continues to the equipped crests. The priority of any equipped crests is relative to the position in the unit's inventory.