AbdulAlhazred
Legend
I'd much rather see 5E create a system that makes severe injury and death more realistic, interesting, and fun, rather than see healing surges be sacrificed on the altar of trying to turn HP damage into something it is not.
The real problem with a realistic system is that damage is non-linear. The fact that you got a cut on your arm 5 minutes ago has little or nothing to do with the potential lethality of another cut you suffer on your other arm right now.
Imagine a scratch is 1hp of damage, and a bad cut is 5hp of damage, and a deadly blow is 10hp damage. Would 10 scratches be lethal? No, of course not, and probably 2 bad cuts wouldn't be either, nor would 5 scratches add up to a bad cut. 100 scratches might add up roughly to a bad cut, and 10 bad cuts might be cumulatively lethal, but realistically the whole thing is very non-linear.
This means 2 things, a simple tally like hit points can't ever be realistic, but also any system that is realistic has to admit to the possibility that you could suffer a lethal injury with no prelude. In real life you don't 'get into trouble' and then die, you mostly just die right off regardless of what came before. Clearly this makes both simple bookkeeping and playably gamist rules both entirely incompatible with realism, at least within the context of a system that uses something roughly like hit points.
I can imagine a system that might be both moderately realistic and also gamist enough that it might work, but there's no chance at all that it is going to be incorporated into D&D, not even as a module, because it would have to entirely redefine what damage IS (and various other things too).