4E D&D Hack: HP costs on Powers

I made a twitter post about this, and I decided to blog it as well for posterity. I'll also adjusted some theories and numbers, expound the reasoning behind this hack, and showed what to expect in game play. You can check the original twitter thread here.

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So first, I'd like to point out the idea of HP from 4E D&D, seen on page 293 on D&D 4E PHB.

HP =/= Life Points.

So we're extending the meaning here of HP as stamina and mana as well. It's more than just health points. Hit points help you stay alive and able, and will now fuel your strongest of powers.

Now the key change is that you still play 4E DnD as is, except powers with Encounter and Daily keywords now have HP costs, regardless of power type (class, racial, utility, theme, etc), and you are no longer limited by their casting limits. These are some new rules:

• You can now cast any powers many times, as long as you have enough HP to do so. No limits.
• Encounter powers costs power level times 2 HP to use. Encounter (specials) costs the same.
• Daily powers costs power level times 3 HP.
• At-will powers are unaffected; they are your bread and butter and don't cost you effort to use them. 
• HP reduction for the power costs happens BEFORE the power happens, so if you suddenly lose consciousness while using a power, the power fizzles.  
• For unleveled powers (from classes, races, themes, etc), use the minimum level to use the desired effect of the power for computation. 
• Example: Clerics' Healing Word power has no level. If they are level 6 Cleric, they can cast it as a level 1 power (regain HSV + 1d6 HP) for 2 HP, or as a level 6 power (regain HSV + 2d6 HP) for 12 HP. 
• You cannot use powers beyond your own level, even if you have the HP for it. 
• Example: As a level 1 Cleric, you cannot use Healing Word as a level 6 power. 

This is also applicable to monsters powers and abilities. Count recharge 4-6 and 5-6 powers as encounter powers, then recharge 6 powers as daily powers for computations. 

[Design note: in my tweet, I originally proposed Encounter = Lvl x 3 HP costs, and Dailies = Lvl x 5 HP costs. But I failed to take account that 4E HP progression does not have Con modifier per level, instead Con modifier goes in healing surge usage. So it's all front-loaded 1st level HP, but steady HP per level. Doing a 5 per level HP costs for dailies would kill a 29th level Wizard for casting 1 daily spell of their level, since they only have 4 HP per level. So I readjusted my proposal.] 

So now that's done... 

One of my favorite art in 4E PHB. Paladin praying before whooping your ass.

WHY DO THIS?

• HP in 4E is pretty bloated, not just because it has a high number at early levels, but because of how easily you can replenish your HP with Healing Surge usage at higher levels. 
• 4E powers' unoptimized damage values are pretty low at higher levels, and can't whittle down enemies or characters fast enough to make decisive moments clear. 
• This way, HP also becomes a resource that you need to check if you have enough, rather than a tracker that you just don't want to go to zero or less.
• It helps in pushing the game away from a videogamey mindset with non-diegetic phenomena of encounter and daily limits. No more spamming short rests or long rests to recover encounter and daily powers, respectively.

WHAT TO EXPECT:

• Given the HP costs of high level powers, people may consider getting more decent low level powers rather than just getting the best highest level power at all times. 
• To elaborate, at level 1, a Warlock with 12 Con has 24 HP. They can spam level 1 enc and daily powers at a certain point. 
• A level 15 said Warlock with 12 Con will have 94 HP. Casting a Level 15 daily power costs 45 HP, and a level 13 Encounter costs 26 HP. Hard to spam those. 
• It will probably not make early levels too gritty, but casting high level powers will definitely take a toll and make long sessions taxing, especially battle gauntlets.
• Expect a lot of bloodied effects getting triggered faster than usual.
• Powers chosen at higher level will be either finishing moves, game/battle-changing effects, or life-saving powers. 
• No more spamming of encounter powers every short rests without consequences. Make them pay for using excellent moves. 
• Since immediate magic effects are costly in terms of HP, maybe rituals will be more attractive options to avoid or prepare combat encounters. 
• Characters with At-will reliant builds using feat tree builds with gross over-dressed magic items will still be strong. This hack won't address that, especially the magic item issue of 4E. I think that's a separate concern.
• Using healing surges out of combat will be more common place, rather than waiting for surge usage riders from Leader Powers. 
• Combat will still be exciting, but it will still have costs when they wipe out a combat encounter using their powerful dailies/encounter powers, even if they did not get attacked or suffered no monster effect. HP costs will be there. 
• Given that HP and Healing Surges per Day will be used more often now, it should push people to try other methods in resolving situations. You know, talking. Or ambushing. Tactics and strategy beyond the grid. 

HOW TO HACK THIS FURTHER: 

• Make it more intense. Make encounter costs 3 per level, dailies 5 per level. It will be very unattractive to get high level powers with mediocre effects since some can bloodied or even kill you outright. And some powers will definitely not worth the HP costs. 
• Keep the limits. Essentially just taxing characters using encounter and daily powers, and powers still need to be replenished with short rest and long rests. Keep things from getting too power explosive. 
• Give at-will powers HP costs too. You can put in 1 HP cost per use, more for higher level use (at 11th level and 21st level, at-wills deal more damage). I don't endorse this, as I think this is too much. It does force people to make use of basic attacks and basic combat options during combat, and may push people in avoiding combat altogether. 
• Make the HP reduction happen after the power resolves, rather than before. This could make cool, "this is my final moment" actions to defeat an enemy or save the party. Very pulpy and action-focused. 
• Adjust costs for some keyword powers. Maybe Reliable powers are half the cost, or no costs until they hit. Maybe give costs to powers with Sustain. Maybe Encounter (specials) are half the cost. This is more case-to-case basis, as I personally don't want to create more HP cost computation per type of power in this post. Do as you see fit. 
• Allow players gaining and using powers beyond their level, and making them spend HP accordingly. I like this one, endorsing exploits, prayers, and spells as something you can get as a reward or treasure, rather than just abilities you gain during advancements. If I get a scroll of Meteor Swarm (level 29 spell) at Level 13, I can potentially cast it losing most of my HP in process. 

If you have comments or suggestions, feel free to comment!