Since he was the one who arranged for the others to demonstrate their skills to Trumpkin, I'd say his skill was...organization? Strategization? Not sure what a good word is. He also demonstrated it when coming up with the duel with Miraz to stall for time, picking which soldiers to be messengers and referees, and avoiding offending Reepicheep by not choosing a member of his species for either. 

Posted by: @col-klink

Since he was the one who arranged for the others to demonstrate their skills to Trumpkin, I'd say his skill was...organization? Strategization? Not sure what a good word is.

I suppose you could say his skill is "leadership". I always have mixed feelings about declaring a character as a good leader (because the writer can often say they're a good leader without proving it), but I think Peter does a pretty good job as a leader throughout this scene.

He preempts an argument between Edmund and Trumpkin, and figures out an elegant way to demonstrate that the Pevensies are the kings and queens they claim to be. He demonstrates both an emotional and practical level of leadership all in this scene. (Yes, he later demonstrates poor leadership by trying to pawn off the difficult decision of whether or not to believe Lucy to the rest of the group, but characters make mistakes.)

Admittedly, part of me just likes that interpretation because it gives us insight into why Peter would be the High King of Narnia, beyond just being the oldest. Or, perhaps that was a skill he learned because he was High King. Either way, it gives Peter a dimension I like.

I thought about the leadership thing too, but I think Peter's skills come out in other places and other ways.  Like when he tears off a bit of his shirt and tries to make a torch - resourcefulness, or just experience in this type of adventures.  I wouldn't have thought of that.  Or the time he fights Miraz (as someone else points out) - he also was a great swordsman.  And as an oldest brother myself, I've always liked how he seems to look out for his younger siblings; I can't think of any concrete examples in PC, but LWW is full of them (the fight with Maugrim being the most obvious).  Sure he made plenty of mistakes, as we all do, but that just makes him more real.  But specific to that scene, I'm gonna have to just agree, "leadership". 😀

Peter is a leader and ideas guy.  He is sort of the glue that holds his family together.  He recognizes the talents of others and how to utilize them.  He has his moments of weakness like when he ignores Lucy seeing Aslan on the cliffs in "Prince Caspian".   And don't forget he is a tough warrior too.  He probably thought fighting Trumpkin to "prove who they were" was not a fair fight.  And if Trumpkin lost to the smaller brother then he'd have to accept Peter was an excellent warrior too.  I'm also a first-born so I identify with wanting to take responsibility for your younger siblings.  The urge to "parent" them is strong too!