We don't use wounds, but I though of incorporating some sort of lasting injuries for a more Lord of the Ring-esque game that never happened.Assuming that the group really wants it: What triggers would you use to decide to give a player or enemy a wound, such as a break, sprain, etc...? Failed death saves? Critical Hits (maybe after a saving throw)? Taking damage that brings them below a certain threshold?
I felt that suffering a critical hit happened too frequently, and that it shouldn't be systematic on going down to 0 hp so I had decided to trigger lasting injuries on failed death saves only (regardless of margin). Some failed saving throw/ability check could trigger one too, such as failing an Strength (Athletics) check after falling and at least one d6 produced a result of 6. Basically, there were triggers and then some sort of confirmation roll by player (death save, athletics check, Con saving throw, etc). I'd have to dig that document up.
I had also considered a system allowing players to willingly choose one lasting injury in exchange of remaining at 1 hp after taking damage or going back to 1hp when dying. It had the advantage of including more abstract injuries such as "smashed shield" or "killed mount". Each injury could only be taken once in a character's career. Death was even a possible choice allowing for the "it is too late for me my son, tell your sister you were right about me" trope when a player got through all possible outcomes, I guess? That system never passed the first draft stage.
I also heard of homebrew that triggered a lasting injury upon failing three death saves, whereas death was only one of the possible outcomes.