Also, if you like the idea of different types of damage requiring different types of healing (and this is starting to get off topic so I'll keep it short and we can split off into another thread), something like the Stress + Trauma option in Cortex Prime might fit the bill. Stress is 'generic' (and also affects your effectiveness in Cortex, wouldn't necessarily need to in a D&D variant) and when it's depleted you are taken out until the next scene, where you gain a starting amount of Trauma (that also affects your effectiveness) that is keyed to and related to what took you out. Stress recovers quickly, but Trauma does not, and what's required to recover Trauma depends on it's type. Could strike a good balance between generic HP for quickness and more specificity when someone goes down.