Thinking about it again, I think hit points weren't initially planned as "encounter based resource". The effects of Wands of Cure Light Wounds weren't understood when the game was designed, otherwise items like the Ring of Regeneration would be less expensive.
Even later (Savage Species, 3.5) it wasn't entirely understood or used, because Fast Healing and Regeneration cost a lot "Level Adjustment"-wise.
The encounter design / rules for XP as described in the DMG tells us that characters should gain one level after roughly 13 encounters against ELs equal to their level. Ultimately, I have seen few adventures that actually use this rule, and I certainly tend to ignore it most of the time, too. Such encounters are usually not that interesting, as the risks involved is low if hit points are regained between encounters. They are nice for letting the players have some fun with their new abilities, but not so great if that's everything they fight.
2Rodrigo Istalindir:
The "counter" to this in D&D and probably also MMO games is to crank up the difficulty of the combats. Wether this is actually a good counter is certainly questionable. (It certainly works in the way that the combat is still "balanced", but how does it affect the fun of the game?)
But I think there is also still a big difference in D&D and MMOs (WoW) or Action RPGs (Diablo II, Titan Quest) - most of these games feature healing and mana potions that work pretty effortless and instantly, but in D&D, healing during combat is very expensive (since it costs valuable actions)
billd91 said:
I can sort of see the OP point, but hp only look like an encounter-based resource because the players are burning other resources to make it appear so.
That's true, to some extend. The comparative cost of healing is pretty low at higher levels, which means the resource cost is probably not well balanced against its usefulness.
How would D&D played without cheap healing magic?
Would Clerics and Druids be forced to heal the group to full health with their own spells after each combat (which would mean that the group rests even earlier, as the spells are through a lot quicker)?
Or Would the characters become more careful? Is it even possible in D&D to play "careful"? You can try retreating if an encounter turns out to difficult. But stealth and scouting is a pretty limited option due to the specialized nature of classes and skills. Running away is also not easy for everyone (Halfings, Gnomes, Dwarves, Heavy Armored characters).
If the only reaction of players is to rest earlier and more often, changing the rules regarding healing is useless, except in the few instances where the adventurers are under time constaints.