State of mind: In character, but will attempt to win the battle. Characters will not give up of their own accord. That means a character that is uninterested or sees no chance of winning won't simply leave and characters wouldn't simply become friends with each other. This doesn't prevent a character being made to give up, because the other character manipulates them via things like, for example, mind control, fear inducement, psychological tricks or superhuman charisma.
Each character will view their opponents as enemies, who they have to assume wish to cause them severe harm such that losing could have any range of dire consequences. The characters will assume their opponents have not been forced into battle. They are assumed to have decided from free will to fight and are not excused by a just cause, difficult times or otherwise exonerating circumstances. Furthermore, the situation is assumed one where the opponents are not protected by social norms or consequences, such as being a civilian protected by law.