Usage Dice for Hit Points: an Optional Rule
This is a supplement for any system that uses HP. It keeps the HP¸ and treats it purely as a measure of a PC's remaining ability to avoid injury. The injury itself¸ however¸ is tracked with a die whose size increases as a character gets more injured. This die is called the "Hurt Die". The Hurt Die is like a usage die¸ for your body¸ except it counts up¸ not down.
When a PC is hurt¸ the Hurt Die is rolled¸ and a table consulted. The effects of the table produce further fictional effects to getting hit¸ which keeps the narrative of combat interesting. HP is only spent to represent the PC's dwindling ability to dodge¸ affecting the roll on the table.