You can actually use the Soft/Hard HP solution without the RPG officially supporting it. In D&D, you could have the last 10 HP represent lasting physical damage and anything at death's door require a roll on a table that includes losing a limb, massive knee damage, etc.

...and yet there is something to be said for running through a random dungeon and continuing your solo play on the subway on the way to work.

As I ponder how to monetize it enough to continue putting out content, shaving off some development time is definitely a consideration.