D&D 5E Fighter Non-Combat Ability Brainstorm

[snickersnax]

I wonder if we could tie skills in somehow... what if they get various things depending on the skill they have trained for instance the insta knowledge you mention sounds like investigation or insight. All fighters can do it..

I admit to wanting more ways skills and mental attributes have an impact on combat and the fighter

I like this idea. The out of combat skill that I associate with real-life fighting is recognizing and being physically dominate. The fighter's social dominance reflects that mind set. It isn't the witty persuasion of a bard, or the cunning deception of a rogue or the social haggle of a merchant. The fighter uses confident intimidation, in its most subtle form others don't recognize even they are intimidated, because this is not a deceptive intimidation where you are trying to make yourself seem more powerful than you are, it is a pure-truth intimidation where you are just stating facts and consequences.

A smart fighter will know the outcome of the fight before the fight happens. So a smart fighter only takes the fights he knows he has already won. Confident of his ability to predict outcomes he is able to convince other to surrender without a fight.

So perhaps Know Your Enemy could result in an additional mechanical benefit like advantage on intimidation if the information you gather demonstrates that you are stronger.