From How to Fight Write:
I have a scene in my book where the two main characters fight soon after meeting one another, in an area where no one else gets in their way and they have a lot of flat empty space. Both are very skilled, but only one of them has weapons. It’s set in medieval times, so they only have daggers and such. The character that isn’t armed needs to win, and I’m not entirely sure how, realistically, he would.
I’d ask what two highly skilled characters are doing getting into such a silly situation when they know better, especially the one caught without their weapons. However, real people do stupid things too. For all I know, they might of been drinking. Just know, the higher the level of training then the less likely it is for two characters to fight when they don’t absolutely have to. Justification is good. Make sure you’ve got a reason for them to fight that feels natural for both characters beyond needing them to fight for the plot. I don’t know why they’re fighting, for all I know it could’ve started off a drunken row with one yelling, “Anything you can do, I can do better! I can do anything better than you!”
These characters don’t actually exist, but it’s important to get yourself in the habit of thinking they could die. I could die is one of the major thoughts that will occur in the mind of anyone who is highly skilled, and more likely to occur than it is with someone who isn’t sufficiently trained.
. . . .
The soldier understands that violence is unpredictable, that death is sudden, and no form of combat is ever truly safe. One mistake is the difference between life and death. Characters who are skilled will avoid violence because they understand its costs. They have nothing to prove. Remember, a knife is one of those “hell no” weapons. No one wants to be anywhere near a knife when they’re armed with one of their own, much less unarmed.
I could die. Is this worth it? I don’t want to die. Is this worth my life?
Often in well-written fiction when you’ve got an incredibly skilled character jumping into fights all the time for no real reason, it’s because they have a death wish. When someone does want to die, simply doesn’t care about living any longer, or sees themselves as already dead then that changes the stakes. There’s also, “I like to fight” which often translates into “I like to kill” in regards to unrestrained violence. Unless there’s a rules set down, two highly skilled characters have an excellent chance of killing each other. The weapons one of these characters has brought to this fight, say, “yes, I do intend kill you. I will make you very dead.”
Link to the rest at How to Fight Write and thanks to Elizabeth for the tip.