Celebrim
Legend
But more likely I'm not fully grokking the issue?
So the issue, such as it is, is the extent to which the semantic change essentially alters the process of play. Complicating that is that without a doubt the change in perspective about play can itself alter the process of play, simply by changing how the players want to or expect to play.
Most people seem to be focusing on the change in semantics has freed players to narrate their actions and the outcome of their actions. The problem that I have with that is that a GM simply prompting the player to provide narration seems just as likely to accomplish, or not accomplish that same effect. So, for example, this change in perspective could have prompted the original poster to then prompt the players for narration, and it's that asking the player to provide a certain process that is the real factor in the change in play.
For example, at some tables a player is required to provide dialogue when their character wants to influence the game world via a social skill, while at other tables the player is only required to state their goal. That's a change in procedure that doesn't seem to require a change in perspective about skill checks, since some groups do it and some groups don't usually based on a bunch of other factors. Some writers have I think improperly tried to link the idea of dialogue to the rules of an edition of a game, and have suggested that because of the rules of edition X, you can't use dialogue or are forced to use dialogue. I don't find that argument compelling, not only because it goes against my own anecdotal experience. In practice, I think that this is a proxy argument that people advance to justify their own preferred edition, and as such it's just 'edition warring'.
I think simply making the player roll damage (now called "defense" or something) to find out how difficult it is to fend off the successful attack is all that's need to adjust to this definition of HP?
Not so far as I'm concerned. That would to me be another change without real substance.
So a real change where hit points were spent...
Imagine combat works like this.
a) One party proposes to enter into a combat.
b) The two parties state the goals that they have in the combat. So party one may say, "If I win, your dead and I get to eat you." And the other party says, "If I win, I get away safely carrying a valuable treasure, and your character won't be able to catch up for the duration of the adventure."
c) The two parties then bid their "hit points" from their hit point pool based on how badly they want to win. In this case, the stakes of the combat are unequal, so we'd expect the party that is going to die if he loses to bid all or most of his remaining hit points, especially if the combat is relatively equal. The two parties can take turns raising their bids until both have gone "all in" or "called", at which point we deduct their hit points.
d) We then resolve the combat by some fortune mechanic, say each party rolls 1d20 and adds the bidded hit points plus there combat skill bonus, with the higher total winning. Once we've determined the winner, we apply the stakes set in step B.
In this case, the players really are spending their hit points. They do not have to spend hit points, but can strategically outlay hit points as a resource in hopes to mitigate luck and/or win the combats they really care about.
The problem I have is that simply saying that a person is "spending hit points" when in fact they are being forcibly deducted as a the result of an attack, and not spending hit points isn't really a choice nor is determining how many hit points to spend really something you can choose, doesn't really feel like it ought to change the process of play. But apparently, for some it does?
Rather than focusing on the narration change as the substantial change in the process, I'm focusing on something else as a potentially much more substantial change - fortune at the end rather than fortune in the middle. (Note that the hypothetical D&D with hit points as narrative currency I outline above also uses fortune at the end.) But so far, I haven't gotten any takers to engage with that perceived change, even to the extent of affirming or denying it is happening.