At first glance, the biggest loser is the assassin rogue. It becomes much harder for Assassinate to take out or cripple one enemy at the start of combat.
Healing resources become tighter. Hit Dice and cure wounds heal proportionately less of a character's hit point total. So the party can push harder and perhaps paint itself into a corner more easily. (Still very forgiving compared to previous editions, though.)
I might be okay with that. I had an assassin rogue take out what was supposed to be the big baddie of a fight in the opening round once, so I cheated and doubled it's HP. As long as a game with an assassin has a suitable number of mooks and lower CR threats, it could still see use.
Healing does prove tighter within a single combat. Aside from this, I have been looking into switching everything over to short-rest recovery, and using some other mechanic for long term HP damage. With the healer feat , healing tends to be pretty easy to come by already. Potions are cheep too.
From the third angle, if you bump everyone's HP, you'll still see that weight toward controlling effects over damaging effects. Action denial becomes more potent the more actions you can deny. The more crits/recharges from monsters will be offset by more HP, but the main thing is that PC's will run out of novas faster. The later in the adventuring day this gets, the more the party is going to be out of "interesting actions."
If your goal is longer combats, a less dramatic way to accomplish that goal might just be to phase in a second encounter after the first. PC's can take two encounters in a row without stopping just fine, and phasing them like this extends one combat, but doesn't make individual monsters stick around for any longer.
Definitely doing this for everyone: PCs, NPCs, and Monsters. I like the idea of reducing novas. I despise novas. The concern of the timer on "interesting actions" is one to watch out for. The only thing that made 4E's long encounters boring was everyone blowing their encounter powers first and having "just at-wills" afterwards.
Phased encounters is an interesting idea, but I can't do that all the time.
The monsters gain a little more than the characters do, by half 1 hit die minus 1 point, as the PC's first hit die is already maxed, but the monster's is not.
Possibly. Monsters have a lot of hit dice, though, and a lot of HP compared to players, so it could still work out in their favor.
Off the top of my head:
- Weapons and damaging abilities/spells now half the effect (in terms of percentage). Before if it was 4 hits to kill a foe it will be 8.
- Buff/debuff/battlefield control have about the same affect, maybe more because combats are going longer (more use out of a buff/debuff, split combats into smaller combats, etc.)
- CON does less for total HPs, has about half the effect. (But still has same affect of HD)
- Difference between the hit dice size is now 2 points be step instead of 1. So before there would be a 3HP/lvl differece between a rogue and a barbarian and now it's 6.
- Single use effects (many spells, divine smite, ki, etc.) will have more chances to be used so could be the same effectiveness at the cost of a much higher use rate.
I like the sound of a lot of that, actually. Damage spells (and the damage spell that is the barbarian) have been unclimactically ending our fights as of late. Longer fights do mean more chances to be hit and lose concentration, which could balance buffs. Con having less of a direct effect is good; maybe people will feel that Con 14 is less of a necessity (though I'm sorely tempted to change how con applies to HP anyway). Rogue and Barbarian HP is 8 to 12, assuming same Con (rogues are d8, right?).
Do you really think more rounds offers more opportunities to use ones abilities? That could be an interesting side effect if it works out that way.
