Had the first full-contact playtest of the Heretical D&D project. Had four playtesters in attendance, and a lot of good back and forth. 

Let’s see what I can say without giving the game away.

Notes and observations in play

In no particular order, I found that there were some gaps in how I account for armor that will come up even at first level in some classes. It’s an easy fix, but needs to be there.

The settings for how hard it is to hit foes got a last-minute tweak yesterday and it worked out very well, or at least well enough that it wasn’t broken. 

When you hit, you hit, and you knew you hit. This drew zero comment, which means that the narrative and the mechanical were unified enough to, well, not draw comment. That’s a win.


Tactics were huge. When it only took a few blows – or even one – to injure or kill, how you faced the bad guys really mattered. Flanking was huge, and funneling the foes down into a narrow doorway (stupid kobolds! no biscuit!) turned it into a meat-grinder for the NPCs. We might even reinforce this, and consider facing as a mandatory thing. 

There are a few fiddly rules bits that require consideration, because there are plenty of times when taking a moment to do something other than the equivalent of “do moar hit points!” was important. So this needs to be clarified.

With armor as a reduction in damage, we need to think about putting multiple layers on. Leather underneath chain? Mail under plate? Stacking damage absorption works from a mental model, but doing so needs to be an issue, or have a cost, somehow. Disadvantage? Reduced move? Can’t Dodge?

So that was the in-play commentary. What about after the bodies had stopped twitching?

Post-play feedback


Everyone agreed that armor absorbing damage just worked, and was super important to the feel. Likewise, shields are a big deal, especially at low levels. Strapping on a shield was decided to be a full-turn action, and the setup of robustness vs injury was harsh enough that not taking that time cost an NPC his life. That being said, some NPC-vs-Boss/PC distinction in how that’s handled was suggested, and will be incorporated. It just makes sense.

Pre-game prep has a few more precalculated values, but once they’re there, the entire character’s guts can be written on a 3×5 card. We are not turning D&D into GURPS here.



There was grappling! And it was useful, but not an “I win” button. The rules for how much effect that a bad guy can deal (or a good guy, for that matter) did not cause an issue. I really liked how it played out: Patrick’s character grappled a hobgoblin and did enough control to make him Restrained (advantage on attacking him), which made short work of the hobgoblin. This seemed very monkish. Need to add the grapple and control maximum to the character sheet, though.

A tweak I made for bows in combat worked out well, and counterbalanced a design element which would have been problematic without it. Yeah, yeah, cryptic. I know.

MAD! – In post discussion, there was a strong vote in favor of DEX always adding to hit, and STR always adding to damage (multiple attribute dependency). Need to figure out what Finesse weapons mean in this context, though.

This was not GURPS, with all the skills and all the fiddle. It was also not 4th or straight-5th edition D&D where you whack away at a giant pile of hit points. Kobolds would go KO in one or two blows – usually one. Hobgoblins, in their armor, were a real threat, and they rolled pretty poorly. 

Overall, this did not seem broken to me. Emphasizing tactics through facing and flanking, and lethality through the importance of armor was all good stuff.

Two more playtest sessions schedule for this weekend, and we’ll see how that goes. Only about 1/3 of my tester pool has actually played the game with me yet, so there’s a lot of room for “this blows!” 

But the initial contact with the enemy shows both the strength of the foundation 5e system as well as the fairly compelling nature of the rules alterations. 

So . . . onward!

Two things are taking my blogging time right now.

First is that +Jeffro Johnson is helping me get acquainted with the PERL script we use to get the GURPSDay thing going. His ownership and authorship of the script was always supposed to be temporary, but he’s just so efficient that we never really completed the knowledge transfer. We got 35 of 37 blogs pulling properly, but two outliers will take more wrestling.

The second piece is the D&D project, on which I made ridiculous progress and then last week hardly any. That’s not a slow-down in intent and commitment – I still know mostly what I want to do with it, and in a few more days, if I don’t hear from one guy, I’ll start with the “what do I do on X and Y” final commits. I’m planning on staging some test fights this weekend, too. Once I settle a few “what do I do” questions, it’s a matter of pounding it out.

I’ve been getting great advice, too. And help with still more. I chose better than I knew when I picked my playtesters, too.

You’re going to be hearing less about this, because I’m in full-on writing mode. I’ve got enough to write up a real set of rules, and thanks to the SRD, this can really be made into something cool.

Where am I?

I’ve got an outline. I’ve got a title for the rules that I don’t think has been used before.

I solicited and received an offer for layout help, and it’s going very well. He’s using the project as an excuse to learn InDesign, and I’m digging the process of getting my head into a D&D product for real. This is going to look like a D&D5e cousin – recognizably from the same gene pool, but definitely not the same direct parents. 

I’ve got about 2,600 words down so far, and the writing is, thus far (and dare I say it?) easy. It helps that I’ve written a bunch of it before, and extending my concepts to the SRD is proving fairly easy.

I’ve got a “productization” strategy in the works, too. I think it’ll please people.

I’ve also got a good group of trusted playtesters, game authors all, who have volunteered to play this when I’m ready. I’m not going to take that long to get to a test, either. A bit more transfer of concept to the page, and we’ll probably start a game and see if the rules survive first contact with the enemy. This is a closed group for now – I can rely on them to play the game “as is” for a while, rather than try and overwrite my authorial intent immediately. That won’t prevent them from saying “I don’t like X, it sucks.” They will let me know this. But they will soldier on and play it as written, and then play it again with tweakage. At some point, I’ll ask for people to try it out with their own groups, because not everyone gets to play the game with the system designer at the table.

But for now, I’m quite pleased. 

Since my original forays into tinkering with the combat and narrative mechanics in D&D5, I’ve written a combat simulator to look at how quickly two combatants can drop each other using my rules assumptions, including for armor.

I’ve found out a few things, which have sent me back to . . . not the drawing board, but the tinker board, at least.

Why all this effort? Mostly for fun. I’m not sure I’d run a game this way . . . but I might. And if the rules work out as fun and usable as they appear to be, perhaps there’s a product in the future. Stranger things have happened.

On Your Mark, Set . . . Calculate!

The first thing I did was to start simulating this stuff using Excel as a Monte Carlo engine. Tens or even hundreds of thousands of attacks, looking for the average time it took to drop a foe, relative to the usual way.
As an example, if you take the rules as I noted them in a prior post, with a base stress threshold of 6+DEX Bonus+Proficiency Bonus, so that your Stress Threshold is 10 and your Impact Threshold with a shield is 14, then you wind up having two first-level fighters each take about four attacks to bring each other to zero stress points . . . but the average number of hits you need to kill the foe goes up with my system. So if two first-level guys fight until they start taking wounds, it’ll take about the same time. If they fight until they die, it’ll take longer, with a lot of fighting after the first sword hits flesh.
Here’s the simulator so you can try for yourself. Feel free to suggest modifications.
What about higher level characters? First-level guys are pretty fragile. And they have more stress points by virtue of carrying a shield (20) than they do from their rolled HP+CON bonus (12) assuming STR 16, CON 15, DEX 14.
How about the upper end of the +2 Proficiency tier? How about a Mountain Dwarf 4th level fighter, with STR 18, CON 18, DEX 14 (Tavern Brawler Feat)?

Well, the hits per kill are now within a few tenths of each other – about 13 attacks to fell an equivalent foe by RAW, and just shy of 12 with the new method. So the new rules has fighting to the death about equal, but the defender will take “real” wounds in about half that time. That assumes chain mail and a shield with a 1H weapon like a sword or axe.
Crank it up? Lower end of +5 proficiency – 13th level. Now we add two attribute score increases, bringing both STR and CON up to 20 (!), and the Alert Feat for that lovely +5 to initiative. We’ll ignore magical weapons for the moment, but we will give our dwarf plate armor. We leave DEX alone because it’s capped at +2 DEX bonus because of the heavy armor.
Fighting our prior 4th level character, he’ll be wounded in 5 attacks and dead in 9 in the new system (and 8 in the old). He’ll threaten the 4th level character (cost him stress) every time, threaten an impact 80% of the time, and 82% of his impacts will actually cause wounds once stress is depleted. 
Against an equal foe, by RAW it’ll take about 30 attacks – and with three or four attacks, that’ll be 7-10 turns. With the new rules against a guy with a shield and plate, it will take 16 hits to lower stress enough to wound him, and a further 8 hits to drive him to his wound maximum of 25 (and thus kill him). The skillful fighter will threaten his foe 90% of the time, but strike home only 35% of the time – the double proficiency bonus from weapon and shield (or two weapons, if you allow it) drops the number of “you were good enough to bypass his defenses” hits down by half. 
If the foe puts down his shield, the hits required to wound drops to 12 (reduced by 25%) and the hits to kill down to 18; the impact rate goes up to 60%! Shields matter, as they should. But they don’t dominate the results.
Thus far, I remain pleased with how the combats aren’t that long – or indeed that different at least on equal foes. 
Oh, but what about a 4th level fighter who decides to challenge a 13th level one? 17 hits to wound, and 26 to kill. By RAW, it would take 56 hits to kill, so the playing field is much more level here, but since our 4th level character will be dead in three rounds, our 13th level warrior will have plenty of time to recover his breath. 
Armor Again

The only thing that makes me think a bit more is that even against fairly run-of-the-mill STR values (say a 1st level fighter’s ST 16, with a +3 bonus), you’re looking at 4-11 points of damage, against 1-10 points of armor. That really only protects you a tiny bit, and even with plate blows are not terribly likely to “bounce.” I think that’s as much because my armor is always 1dX rather than (say) 2d(X/2). Or even upping armor values a bit, but honestly, the current system works well enough.
Parting Shot

Like this, but for my rules

I’m sure that I could tweak it up more. But honestly, the values seem to be not-awful and really what it needs now is to be honest-to-goodness playtested. 

The other thing it could probably use is a purpose-built character sheet, which displays the appropriate thresholds and even has some of the key rules, such as an Impact being allowed to be taken as stress if you can absorb 2x the damage roll.
Also, right now, you still have to take the entire damage roll as stress – armor doesn’t mitigate that at all. The point being that “I take the blow on my armor” isn’t really the choice that you make. 
It could be, though! That wouldn’t be hard to re-jigger, merely adding a few other if-then statements so that (for example) you can turn an impact into stress by taking twice the actual injury (so go ahead and roll armor) – but that could get recursive and slow down play. So I think I like it as-is, but would welcome other perspectives or actual play results.
But I think what I’ve got here is a real start at a replacement that makes short and long rests make utter and total sense . . . and wounds be quite serious.
Next up, injury and recovery. 
Because as much as D&D is a resource management game, we need to account for potions and spells. And the assumption that you recover (for example) 10% of your wound maximum every week needs to be reflected in magical spells and potions. 

When last we left our heroes, they (me) had first given some stream-of-consciousness thoughts on revamping what hits and misses mean, as well as differentiating between Stress and Wounds, and slapping on Damage Resistance or an Armor Value as the typical last-ditch defense when the wounding threshold is exceeded and a weapon actually hits the target’s body. Only after all of that is injury suffered.

However, looking at the armor values themselves showed that my initial musings would produce results which, on the average, wouldn’t be consistent with the existing Armor Class progression. Is that a show-stopper? No, but if I can avoid it, I should.

In chatting with some friends the other day, I was forced (in order to make my own thoughts clear) to articulate some of the design goals for this project, and one of them was that when all was said and done, the mechanics needed to feel very DnD. To that end, what I want to accomplish here is to get to something that is narratively more satisfying than the existing mechanics . . . but I want to do it by adding no more than one additional die roll.

I might be able to git ‘r done without another roll. But giving myself the leeway and the limit of one more means I won’t wind up in crazy-town.

Note: this doesn’t mean that one can’t roll additional dice. I have already had one – legit – request to ensure whatever I do works with turning proficiency bonuses into dice. But there will be an attack roll, a damage roll, and a roll-to-be-named-later. Maybe. But no more than that!

So, back to mechanics.

Stress and Wounds

Just for heresy’s sake, wounds count up from zero: so zero wounds is ‘unwounded,’ while higher numbers are worse for you. Stress counts down, just like the HP they replace. 

Wound Maximum: CON + STR Bonus. Wound levels from 1 to half the Wound Maximum (round up) threaten the fighter’s capability. Wound levels higher than this, up to the maximum, threaten the warrior’s consciousness and potentially his life. Exceed the wound maximum and you start the death check process as written.

If you take wounds . . . 

  • If you are at less than half your wound maximum, your rolls have Disadvantage.
  • If you are at more than half your wound maximum, make a DC 10 CON check each time you’re wounded (but not every turn). Failure drops you unconscious. Each turn after, make a DC 10 CON check. Three strikes and you die . . . but any success stops the process. You’re KO’d but not dead.
  • If you exceed your wound maximum, start the usual Death Check process. Three fails and you’re dead.

Originally, I had penalties equal to half your wound level. But that got serious fast, and honestly, that made someone with 25 Wound Maximum liable to pass out at a lower percentage of their max than someone with 10 wounds. I could easily see alternate ways of attacking this. You fight, but at a penalty, at up to half your maximum. Or you take -1 to all rolls to a maximum of -5 as you go from 1 wound to half maximum. That sort of thing. I erred for simplicity here.

Stress Maximum: This is the fighter’s normally calculated HP. Hit dice and CON bonus. The “normal rules” way to play will be that so long as your stress total isn’t worn down to zero, you’re at full fighting capacity. If you have a shield, it adds 10 Stress Points per point of proficiency (so if you’re +4 proficiency, you get +40 Stress from the shield).

This is there to address the complaints that legitimately were asked about shields only being good for +2 to armor class.

The Attack Roll


The prior work established two notions. That of a level where rolling lower than this means that you either swing and completely whiff, or never even swing at all due to lack of appropriate openings on your foe (the second one really only works for melee). That was called (in the previous post) the Defense Threshold.

Calling it the Stress Threshold makes more sense.

Why? Because the upper threshold was the Wound Threshold, above which you start to be at risk of having that sword, axe, or arrow actually hit your body. Even so, because to do wounds a blow has to bypass any armor worn, wound threshold will be renamed Impact Threshold.

So we now have Stress Threshold and Impact Threshold.

Again, the prior work showed (well, showed me . . . I didn’t publish this result) that even without rolling to hit at all, certain armors were so tough they more or less dropped the expected damage threshold to nearly zero (or at least zero most of the time) even if you just stood there.

Attack a guy in plate (average protection 7.5 points of damage, or 1d12+1) with a dagger at 1d4+2 and if you don’t roll for armor, only a critical hit (2d4+2) will get through, ever. If you do roll for armor, accounting for crits on a 20, 1d4+2 against 1d12+1 will come up with zero damage 78% of the time, and when there are wounds, will have a median of 2 and an average of 2.12 (and a maximum, of course, of 8).

So just by virtue of the armor itself, that’s roughly the equivalent of an AC of 16 or 17. You don’t even need anything else – defenses, nimble footwork, or whatever – to stand against that.

That’s not a bug, in my mind. Dagger vs. full plate should be a smackdown unless you have an unaware or unresisting or untrained foe. What about the other end? A 1d12+4 weapon? You can get some seriously ugly wounds (up to 26 HP) through the armor, and if a blow strikes, you’ll do at least one wound 70% of the time. So don’t bring a knife to an axe-fight, and you’re OK.

Stress Threshold


Let’s hit some design goals, narratively speaking.

It seems to me that my pre-determined “you miss” results either mean that you do swing and you biff it, or you never really get a chance to strike at all.

Now, all of that assumes two mobile, aware targets. Never get an opening assumes some maneuver and posturing and feints and footwork, yes?

That seems like Proficiency should play a role, then. More experienced fighters should be harder to force into a position where a strike is even possible. OK, the minimum bonus for proficiency for Level 1 characters is +2. Goes up to +6. Good to keep in mind.

What about DEX? Should natural nimbleness make it harder to put you into a position where a strike is possible? If you say “yes,” then for PCs you’re looking at a usual range of about DEX 8 (lowest number in the standard array) to DEX 20 (usual maximum), or -1 to +5.

If you say that dancing about is stressful (or exhausting), and that any use of proficiency involves motion and skill, then all fights have the same target number for a miss. That doesn’t seem quite right, though it’s defensible, I suppose.

On the other hand, the range of both DEX and Proficiency goes from +1 to +11. That could mean that if you’re adding that to a base of (say) 10, that you won’t even cause stress (which are basically HP, renamed, with some slight contextual differences) unless you can roll 11 or higher (50% chance per turn of either no-strike or swing and a miss) on the novice end, or as high as 21 (!) on the high end. You can’t even lay a figurative glove on this character even with his high-leveledness weaponless and shieldless.

The stress threshold implies that below this figure, you’re not even trying hard enough to exhaust skill or luck or stamina. You just don’t bother, effectively.

I’d think this number should be low. Maybe very low, at least for low-level characters with poor stats. I was going to work through various possibilities, but I think I’ll just cut to the chase: Use a base value of 6.

Base value 6


A base value this low means that Joe Average, Level 1 PC with all stats of 10 (+2 proficiency and nothing else), or wearing armor that neutralizes a DEX bonus, will have a Stress Threshold of 8. 65% of the time, he’ll have to react to a foe rolling 1d20+0, and against a fighter who’s purpose-built at first level (STR 16, for 1d20+5) will only be save 10% of the time. That seems legit. 

The worst-possible category will be a net -5 bonus (STR 0 or STR 1, no proficiency) which means you can still miss by rolling a natural 1. That puts the “always miss rolling a 1” and “what’s the worst could happen?” as congruent, which pleases my sense of symmetry and ‘no special cases.’

That might be pretty easy, but then, proficiency-only and crappy stats isn’t a credible fighter – so maybe that’s OK. Our notional beginner fighter with DEX 14 (+2) and 1st level proficiency (again +2) will wind up with a Stress Threshold of 10 in up to medium armor. Again, a 6th level fighter (+3) with STR 18 (+4) will only fail to stress this guy by rolling a 1 or 2.

So two first-level guys in medium armor going after each other will be 1d20+5 vs. a Stress Threshold of 10. Eight times in ten, an attack will cause the other guy to suffer stress. 

What about the high end? DEX 18 and a +4 proficiency in light armor means your Stress Threshold is 6+4+4 = 14. A non-combatant (1d20+2) will threaten this guy 45% of the time, and a decent fighter (1d20+5) will threaten him 70% of the time. 

What we’re really dealing with here is Base + DEX + Proficiency on defense, and 1d20+ STR/DEX + Proficiency on the attack. For equal-level fighters, this will tend to favor the attack by 1-2 points, and the odds of having to not do anything other than footwork are low. Basically 1d20 vs an effective target of 4 or 5, or about a 15-20% chance of a total whiff.

DEX  Bonus and Proficiency Bonus Considerations


The DEX bonus is conditional in vanilla 5e – if you wear certain armor you are capped at a max of 2, or don’t even get the bonus. 

On the other hand, you must be proficient to even wear armor. Proficient. You could certainly have someone strap plate armor on to you, and assuming you are strong enough to move the weight of the armor, it will certainly protect you from blows. 

If I hold to the DEX bonuses from the Player’s Handbook, that means that a fairly expert fighter (say, Proficiency of +4) in plate (no DEX bonus allowed) will have a Stress Threshold of 10. A Rogue in studded leather (full DEX bonus allowed) of the same proficiency may well have a Stress Threshold of 15. Harder to hit, but if you do hit, much less protected.

Impact Threshold


Above the Impact Threshold, an attack will bypass defenses of any sort and strike home. Such a strike, whether rolled naturally (attack roll exceeds impact threshold) or as a result of whittling down the foe’s Stress Points, results in an Impact. Protecting against such is skill-based, so it means proficiency.

Anything that raises Armor Class that feels like defense and active skill needs to show up somewhere. Things that make sense to defend against blows, such as shields and off-hand weapons, need to show up somewhere. Martial prowess from the Monk’s martial arts abilities need to show up.

I’m going to start by saying that you get your proficiency bonus for each weapon or shield (up to two) that is capable of defending against blows. A beginner sword-and-board guy? That’s +2 for the sword, and +2 for the shield. Impact Threshold would thus be 4 higher than the Stress Threshold. The same would go for a guy with a rapier in one hand, and a shortsword or main-gauche in the other.

Two-handed weapon users – greatswords, great axes, and polearms, would only get the single bonus. 

Bows and crossbows? Lacking some sort of close-combat expert Feat, you get no boost over your Stress Threshold for these.

This means that a fighter with sword and shield in Medium armor with DEX 14 (+2) and a +5 proficiency bonus will be looking at a Stress Threshold of 13 (6+2+5) and a Impact Threshold of 23 (13+5+5). Assuming that same fighter has STR 18 or 20, he’ll be attacked at a minimum of 1d20+9, maybe even +11 or +12 if he’s managed to put his hands on a magical weapon. So a high-level fighter has a reasonable chance of bypassing his rival’s defenses and laying his weapon on his foe’s body.

The Impact Threshold is equal to 6+DEX Bonus+3*Proficiency for the most heavily defended fighters. This will be countered by 1d20+STR/DEX Bonus + Proficiency.

The DEX bonus will tend to be lower than the attacking bonus (not always; Rogues and archers will have high DEX, but this will often be countered with lightweight armor). Still, you’re looking at 6+DEX+2*Proficiency vs 1d20+STR/DEX (uncapped).

This favors the defender a tetch. Let’s assume two 20th level characters (hah!) with STR and DEX both of 20 (hah, maybe?) and no magical weapons or armor (dubious, but we’ll see). Stress Threshold will range from a low of 6+0 (armor DEX bonus capped)+6 = 12 to a higher of 6+5+6 = 17 (no armor cap at all). Impact Threshold can be as low as 12 (heavy armor shooting a bow) and as high as 29 (studded leather and two rapiers).

On the attack, our notional 20th level character will roll 1d20+11. This still has a 15% chance of overwhelming the highest possible rapier-dancer Impact Threshold, and will only fail to strike home against a heavily-armored guy with a bow if he rolls a natural 1.

A 1st-level fighter attacking the same two foes (1d20+5) will have a decent chance of causing stress on both of them, but will be unlikely to fight past the foe I’m calling the rapier dancer, but could also represent a viking type with axe, shield, and studded leather armor. Again, this doesn’t strike me as instantly broken.

That which doesn’t seem broken may actually still be broken in play. I’ll later on work out how many turns one would expect to spend getting various foes unconscious given various inputs, and see if it works out more or less satisfying than the current rules. Even if the results are different, it might still work out if one doesn’t take a trip into crazy-town.

Critical Hits and Desperate Defenses


There’s a temptation to look at a natural 20 as an automatic strike at your foe’s body, but I’m going to resist that. Instead, leave the rules as they are, and simply apply these two principles:

  • A critical hit (natural 20) doubles rolled damage dice. This subtracts first from stress, and when stress is gone, is applied as an Impact. It is possible – even likely – that a natural 20 (plus attack modifiers) also exceeds the Impact Threshold, in which case the full damage roll – including doubled dice – will be applied as an Impact.
  • All is not lost! If you have the stress to spare, you can declare a desperate defense, and absorb double the rolled damage (including any adds) as Stress. If you can’t absorb that increased damage fully (and that might be doubled!), you cannot select this option. 

This is to avoid “take damage rolled, double it, subtract that from stress, and then as stress hits zero, halve the remainder and apply it to wounds. That’s a lot of fiddle. Doable . . . but fiddly.

Example: A natural 20 on 1d8+3 would roll 2d8+3 for damage, for 5-19 points of damage. A desperate defense could be declared if you have the stress remaining to absorb 10-38 points. Otherwise, you suffer a 5-19 point Impact.


Impact Resolution

Once you have made an Impact on your foe, you take the damage and subtract armor from it. If using the highly-suggested random die roll for armor, take any hits that impact the foe, subtract armor, and take the rest as wounds.

Parting Shot

The upshot is that one will pre-calculate some basic figures as characters are generated, and other than tracking Stress and Wounds, most actual play should be pretty straight-forward. Roll to hit normally. Compare to Stress and Impact thresholds. If the Stress Threshold is exceeded, roll damage. If an Impact is scored, subtract armor and take the rest as wounds.

The only extra roll is the armor roll, so my original design goal has been achieved. It would not be insane to treat any instances of the Proficiency Bonus as dice – even on the defense. Since that number varies from 2 to 6, double it as usual and roll that die type. 1d4 for Proficiency +2 up to 1d12 for Proficiency of +6. That puts some luck in play, while still more-or-less retaining the same results.

Here are some mundane Examples, simply presenting three Champion Fighters of various levels. No Feats, just attribute bonuses, emphasizing CON and STR because it’s assumed that the initial armor is chain mail, so DEX bonuses are lost anyway.

There are, of course, other types of characters that are challenging here, and Barbarians and Monks come to mind instantly. Still, if the system breaks for the bog-standard DEX-based and STR-based combatants, there’s not much point in proceeding. Nothing above instantly looks crazed, though the addition of shield-based Stress Points pushes those totals higher, the lower Stress Thresholds mean you will take “HP of damage” more frequently. 

3rd Level Sword-and-Board; Chain mail

STR 16 (+3); DEX 14 (+2); CON 15 (+2); Proficiency +2
Melee Attack: 1d20+5; Melee Damage 1d8+3
Wound Maximum: 18
Stress Points: 28 (hit dice and CON) + 20 (shield) = 48
Stress Threshold: 6+0 (Capped for heavy armor)+2 (Proficiency) = 8
Wound Threshold: 8 (Stress Threshold) + 2 (Weapon) +2 (Shield) = 12
Armor Value: 1d10

9th Level Sword-and-Board; Plate armor

STR 20 (+5); DEX 14 (+2); CON 16 (+3); Proficiency +4
Melee Attack: 1d20+9; Melee Damage 1d8+5
Wound Maximum: 21
Stress Points: 85 (HD and CON) + 40 (Shield) = 125
Stress Threshold: 6+0 (Capped for heavy armor)+4 (Proficiency) = 10
Wound Threshold: 10 (Stress Threshold) + 4 (Weapon) +4 (Shield) = 18
Armor Value: 1d12+1

15th Level Sword-and-Board; Plate armor

STR 20 (+5); DEX 14 (+2); CON 20 (+5); Proficiency +5
Melee Attack: 1d20+10; Melee Damage 1d8+5
Wound Maximum: 25
Stress Points: 169 (HD and CON) + 50 (Shield) = 219
Stress Threshold: 6+0 (Capped for heavy armor)+5 (Proficiency) = 11
Wound Threshold: 11 (Stress Threshold) + 5 (Weapon) +5 (Shield) = 21
Armor Value: 1d12+1

Just looking at the high-level guy, his former AC would have been 20. Attacked by his equal and opposite, he’ll be hit 55% of the time for 1d8+5, but he’ll crit 10% of the time. It’ll take about 29 attacks to bring him to 0 HP (neglecting Second Wind).

With the newer system, it’s more lethal. The rate-limit on survival is wounds, not stress, and the “take double stress instead of wounds” rule will come up reasonably frequently – it seems only 10 attacks are required, more or less (my spreadsheet isn’t quite right yet) instead of 29 without that rule.

So more lethal for equal fighters, despite armor as DR. I need to work this more, but my biggest worry was the system would prolong combat, and I don’t think that’s what’s going to happen.

I’ll run more scenarios and get better numbers, but I think things got more interesting rather than less.

In my pondering of heretical D&D concepts from the other day, one of the thoughts that I had was:

Wow, rolling vs. a “Defense Target” of 10+DEX Modifier is going to make even very experienced fighters get hit an awful lot. On the other hand, armor subtracts from damage. How does that balance out?

Guess it’s time to break out Excel. First thing that leaped out at me was that the armor was wonky.

The Armor Progressions Don’t Line Up

I’m not going to show my work here, but the armor progressions for DR don’t work as I wrote them. The short version is that the AC progression sets the value of armor a certain way, and that means that each successive armor that gets a bonus should have some level of improved protection over the next one.

The progression I have, while elegant, creates artifacts that don’t increment well with the AC table.

Consider the table again. 1d4+1 is supposed to be AC 5 based on the maximum roll. That’s all well and good, but when I simulated the dice rolls 250,000 times, it was clear that I made the wrong call here. You need to treat average damage resistance, not the maximum. 1d4+1 averages 3.5 Damage Resistance. So does 1d6. But 1d6 is supposed to be the better armor. So phooey, that doesn’t work.

Now, if I instead treat the current AC bonus as, say, a half-point less damage than what the dice should roll, that gives padded armor an expected resistance of 1.5 points . . . or 1d4-1. Plate, with an expected resistance of a whopping 8.5 points, might be 1d12+2. Let’s keep only 1d rolling no matter the die size, and look at options for appropriate averages that work with the Armor Class scale.

In order to get to plate, we need 1d12+2. That’s a lot of damage. It means a great axe or greatsword wielded by a strong person will still wind up getting “bounced” frequently. Plus (and again, not showing my work), some of the armor values mean that you’re going to need to hit several to dozens of times more frequently in order to get the same HP of damage through. That will make fights last a really, really long time.

So even before we start, let’s give padded (AC 11, or bonus of +1) an expected protection of 0.5 instead of 1.5. If we disallow any bonus more than +1 or penalty more than -2 (and prefer -1 to +1), we get the possibilities for armor dice to the right.

That shows we have a lot of choices, which is nice. I’ve color-coded the light/medium/heavy proficiencies to see if there’s something logical we can eke out of it. Turns out there is.

We can restrict the light armors to rolling d4, and the medums to d6. Heavy armor gets d8 through d12, with d12 reserved for the suit of plate armor, because it’s more awesome that way. Choosing it that way, and re-ordering the table by proficiency then AC (like it is in the PHB) we get a fairly satisfying table:

The only potential problem children are the -2s for Padded, Leather, and Hide, which for the first two means you have a 50% chance that your armor provides no protection whatsoever, while Hide is a 33% chance. That actually helps Hide armor, because on the straight-stat level, Hide kinda sucks. Sure, it’s only 10gp instead of the 45 for studded leather, but it’s basically the same weight, AC, and Hide hits you with a maximum bonus of +2 to DEX.

Parting Shot

This table is more consistent with the Armor Class values given in the PHB, so you won’t get strange results like I did when I calculated armor values based on the maximum protection and allowed 2d4 as the base roll. That had cases where the superior armor in-game was no longer better protection, and while I suppose that could be considered a design feature, keeping the same relative protection values for the armors listed seemed like it would be worth doing. Alternately, there’s no good reason to change it, and it’s easy to preserver.

I like how it wound up. Light armors are d4, medium are d6, and heavy armor is “higher than d6,” with the very inexpensive ring mail (less expensive than studded leather!) having a chance of zero protection. Better buy smaller rings.

There have been some fun threads kicking around on various blogs and forums about the various mechanics and benefits and methods for hitting and not being hit in D&D5 and even OD&D/OSR-based games. 

I started thinking about this hard when +James Spahn linked to a post on shields in D&D over at Halfling’s Luck. That spawned some very thoughtful comments, and left me wanting to step back and come at this from first principles. 

This was also spawned from my realization that the expanded critical hit range mechanic was pretty cool, and perhaps underused.


Hit and Miss – Mechanics

To thwack or not to thwack. Nah, there is no question. Smite low thy foe, and plunder his loot!

Defensive Statistics


At present, without invoking optional rules (we’ll do those later), the basic defensive mechanics are pretty few.

Armor Class: Representing the basic resistance to being dealt an effective blow, where “effective” means “reduces your hit points.” It wraps up being nimble (DEX bonus) as well as the quality of your armor (base armor class). 


Hit Points: This is the obvious one, in terms of avoiding death, but while the quantity is perhaps straight-forward, the narrative meaning is less so. Hit Points go up drastically with level.

Saving Throw: Some damage types (such as against spells, but a trap or explosion or a dragon’s fiery breath is a better example) allow an attribute-based roll to mitigate effects. 

Evasion and Dodge: These class abilities allow a saving throw to mitigate damage. Evasion applies against attacks that require saving throws (half damage goes to no damage) while dodge applies to melee attacks.

Offensive Statistics


Whacking someone is similarly straight-forward.

To Hit Roll: 1d20 plus bonuses, which may be granted by STR or DEX depending on the weapon. Also includes proficiency, which increases as characters gain experience.

Critical Hit Range: Usually rolling a natural 20 on your die roll invokes special rules, such as 5th edition’s “roll all the dice twice” method. Champion Fighters enjoy an expanded critical hit range as they gain levels.

Damage: The obvious offensive statistic, it tends to only improve mildly with level, as bonuses to damage are based on your attributes (DEX or STR, capped at 20 in most cases for a +5 bonus) and any magic or special abilities you can throw down.

Alternate Capabilities


There are certainly more house rules than actual rules. Here are some that bear thinking about, largely because I’ll invoke some of them later.

Armor as Damage Reduction: Several mechanics exist for this, but the basic gist of it all is that armor rather than making one harder to hit, reduces damage directly. I’ve seen both flat reduction (GURPS does this too, as the default way of doing things), as well as a recent suggestion to actually roll armor dice. That one is particularly intriguing.

Shields Will Be Splintered: Other than being one of the better quotes from Theoden King, there are various versions of this, including soaking/mitigating all damage from a melee attack that hits by declaring your shield destroyed. I’ve seen “shields provide partial cover,” though that’s really just the same as an AC boost. I could also see that having a shield means you are attacked at Disadvantage (which is a variable boost depending on your target number, up to +4 or +5 to AC). 


Rules for Rules – Something of Value


One thing here, before we start. If I’m going to toss out the usual way of doing things, or modify it, I’d better have a care for what I’m replacing. To borrow a line that always stuck with me from grade school: ““When we take away from a man his traditional way of life, his customs, hi religion, we had better make certain to replace it with something of value” (Robert Ruark).

So hearkening back to my Rules for Grappling Rules, I will try and keep to the spirit of DnD combat, and acknowledge some of the rules:

  1. Use What’s There – right now hit points come from hit dice and a CON bonus. Attack rolls feature a 1d20, DEX/STR bonus, and Proficiency. Armor stats add to AC, and defenses are subsumed mostly into HP. STR matters for attack and defense, and CON influences HP. Care needs to be taken to preserve the feel of characters built using the old rules.
  2. Make it Interesting – If the new rules don’t make for interesting play, they have no purpose. If they add complexity for no narrative or mechanical gain, they are bad rules. In this case, I hope to add narrative consistency (which I think is good) and will generally make life more dangerous for PCs and NPCs/Monsters alike, which I think keeps tension high, and is therefore interesting.
  3. Reduce Book-keeping where possible – Right now, you roll to-hit, you roll damage, and if you hit, the damage comes off of hit points. Any new rules should keep the same general feel and not require tracking large and varied pools of points. 
  4. Mechanical Simplicity is Best – I’ll add a fourth here, because it ties into #3 but is separate from it. The tendency will be to over-specify, and you will see that as I build ideas. At the end of the day, though, a D&D hit roll is a roll vs. a (single) target number. Stopping the game every turn as a player and GM roll repeatedly to see if that hit is successful is not part of the D&D experience, so should be minimized or eliminated where possible, while still considering such trade-offs so long as they’re familiar (#1) and interesting (#2).

So there. Those are my guidelines, which I will doubtlessly break as I fiddle, and then hopefully glue back together as I summarize.

Hit and Miss – Lights, Camera, Action Adventure Movie

So, you got thwacked, you’re bleeding, right?

Pretty much no. This was part of the discussion from nearly the get-go. In CHAINMAIL (and it’s precursor!) it took multiple simultaneous hits to eliminate a fighter, and Gygax put the following into the 1st edition DMG, p. 82:

It is quite unreasonable to assume that as a character gains levels of ability in his or her class that a corresponding gain in actual ability to sustain physical damage takes place. It is preposterous to state such an assumption, for if we are to assume that a man is killed by a sword thrust which does 4 hit points of damage, we must similarly assume that a hero could, on the average, withstand five such thrusts before being slain! Why then the increase in hit points? Because these reflect both the actual physical ability of the character to withstand damage – as indicated by constitution bonuses- and a commensurate increase in such areas as skill in combat and similar life-or-death situations, the “sixth sense” which warns the individual of some otherwise unforeseen events, sheer luck, and the fantastic provisions of magical protections and/or divine protection.

OK, so that was AD&D, which is a nice historical reference point. That being said, it is a rare gaming table – in my experience – that doesn’t not describe a successful roll against a foe’s Armor Class as a successful strike against the foe’s body. In a game which uses HP as an abstraction of damage, that’s clearly problematic. 

That explanation gets even more problematic when you consider the various healing surges and recovered hit points gained during Short and Long rests in D&D5.

Narration and Mechanics – Getting to the Point
So as not to confuse myself, let alone y’all, I’m going to define terms a bit differently along the way, but try not to reuse common D&D terms unless the meaning is clear. Hopefully I won’t go horribly pear-shaped.

The Quantity Formerly Known as Hit Points


Before we get into swinging swords and whatnot we will define a few basic quantities that will serve as replacements/augmentions for hit points.

Wound Points: Equal to your CON (full stat) plus your STR bonus. So big guys have more wound points than skinny guys, but your CON still defines the basis of it. This does get bigger as your stats change, but does not get bigger with level otherwise. A 1st level Mountain Dwarf with CON 17 and STR 16 would have 20 Wound Points. Joe Normal with STR 10 and CON 10 has 10. If you really were prioritizing other things you could start with as few as 8 (CON 8, STR 10) Wound Points at 1st level. Wound points are slow to heal, being regained at a rate of 1 per week.

If you want math and want to equalize things, 20 weeks per max wound points – so 25 wound points would heal back at 0.8 weeks per wound point, while 8 WP heal at 2.5 weeks per point. Yeah, that’s a while. Yeah, that’s what magic is for.

Stress Points: This is the traditional stand in for HP, and include what is usually rolled for starting hit dice and the normal bonuses to CON. So our mighty 1st level fighter with STR 16, CON 17, and 1d10 for hit dice would start with 13 Stress Points. These represent your skill, luck, fitness and endurance, and a measure of your defensive capability. Carrying a shield will add to your Stress Points, standing between you and harm.


The Attack Roll and the Stress Target – Melee Attacks

The first thing that you’re going to do is try and menace the target. This means that you have to see an opportunity, and also to get close enough to your target during your attack the foe has to react.

For a melee attack, this would be making an attack roll (the usual 1d20 + STR/DEX + Proficiency) against . . . I’m going to go with 10 + DEX Modifier. 

The melee attack thing is important – please keep it in mind.

If you miss this roll, you either don’t seen an opening at all, or you swing and whiff. They dance out of the way easily, the distance is wrong, whatever.

But they do not make you parry, block, frantically get out of the way, or rely on a lucky break. 

In normal parlance: you missed, whiffed, ix-nayed. 

So, your Stress Target is 10+DEX Modifier. With the standard array, this means Stress Target will be, for starting characters, between about 9 and 14. If you meet or exceed the Stress Target, you may either Stress your foe, or potentially strike home.

Stress, Shields, and Wounding Threshold


If you do overcome positioning and throw a blow that might inconvenience your foe, it will cause him Stress. This is the direct analog of HP, but does not in any way imply a blade (or whatever) physically impacting the target. If that happens (more on that later).

But to do that, you must exceed the wound Threshold, which is potentially the higher of two quantities. Your Wound Threshold is your Stress Threshold plus your Shielding Bonus plus your Proficiency Bonus. If you meet or exceed your foe’s Wound Threshold, you actually strike home.

Shields


Shields increase Wound Threshold – it’s harder to get past them. It should be significantly harder, too, because the type of shield that most D&D players will wind up carrying is what GURPS would call a Medium shield, or a heater shield. It’s going to be about three feet tall, and two or three feet wide. Maybe circular or rectangular. It might even be a Kite shield, which seem to be narrower (perhaps 20″ wide at the largest) but longer (3.5-5′ long, I think). Such things are going to be very difficult to bypass.

Your Shielding Bonus is equal to twice the usual bonus to Armor class due to either a shield – so +4 instead of +2. It defines your Shielding Threshold, which is the Stress Threshold plus your Shielding Bonus

Yeah, I’m defining a lot of quantities. They are figured once, though, so shouldn’t slow down the game at all, and should mostly remain static.

Note that if your shield gets hit, it may be damaged or destroyed. So yeah, it’s great to hide behind it, but they don’t last forever.

Note that if you exceed the Stress threshold, you will do Stress to your foe, shield or not. What you won’t do – yet – is strike his person. At least until his Stress Points drop to zero.

I should note I’m torn here. I also like the idea of shield providing Stress Points (formerly known as Hit Points). They absolutely represent a store of defensive capability that has to be dealt with before you can lay sword, knife, axe, or club on your foe. Some literature and film shows heroes utilizing a shield to ward of spells or dragon breath as well (consider the movie Dragonslayer, which features a mundane shield made with dragon-scales; alternately it’s a shield made of magical material made by mundane means). I will likely return to this concept – I think it has value. I’m thinking that a shield should provide something like 5-10 Stress Points x Proficiency Bonus. That way a shield will give the equivalent protection against 1-2 blows from a good fighter – 1d8+3 damage per blow. Two blows will be 4-11 points each, or 8-22 damage, averaging 15. 

For a fighter of level 1-4 and a +2 Proficiency, it might be dangerous to game play to give 10 points per proficiency level. 20 extra “HP” for picking up a shield at level 1? You’d be foolish to do otherwise! And yet ultimately those extra 20 Stress Points represent a few blows only from your foe. So they’ll extend combat by a couple rounds. Against a quality foe with 2-3 attacks, it will be that much faster. A high-level fighter should get more benefit from using his shield defensively through dint of skill, though. Doing it by level would be kinda ridiculous (even though Stress/HP go up every level). So perhaps having it be 10 Stress per proficiency bonus works overall. At high level you get 60 extra Stress, which is maybe the equivalent of 3-3.5 HP extra per level. At low level, shields are worth 20 Stress, badly needed, and worth 5-20 stress per level. There are diminishing returns for having a shield as you get more skilled. I’m not sure that isn’t cool rather than bad.

Oh, and if you don’t have proficiency with the shield? You get no extra stress points, but you do get the shielding bonus, as it does provide cover, though you’re not using it skillfully.

That’s a lot on shields, but then, this entire post started from shields, so it’s to be expected.

Wounding Threshold


Once you get past the natural nimbleness of a fighter, and any shields in the way, your foe is going to have to do something about your blow or else get struck. The point at which you actually see blade connecting with body is the Wounding Threshold. It’s equal to your Shielding Threshold (and yes, that’s also equal to the Stress Threshold if you’re not carrying a shield).

This should be simple. If you exceed the Wounding Threshold, roll damage, compare to armor, and apply hits directly to the foe’s Wound Points. 

If you have exhausted your Stress Points, any remaining or additional hits go right to wounding (though armor still protects).

Failed CON saves from 0 Stress to half your Wound Points risk unconsciousness. If you’re wounded for half or more of your Wound Points, you risk death.

Armor as Damage Reduction


For the purposes here, I’m going to just make the leap and say wearing armor no longer makes you harder to hit. It makes blows that exceed your wound threshold or otherwise strike your body less damaging.

I’m partial to giving each armor dice to roll, subtracting from a blow. In roll20, as an example, this could be built right into the die roller, perhaps even in secret, where both the armor value of the foe and the damage value of the PC are treated as variables, and the program reports only the difference if damage is greater than armor.

So a 1d8+3 (STR 16 with a longsword, a classic combo) damage blow strikes a chain shirt – a nice middle-ground armor. it resists with 1d4+1. Dice are 1d8-1d4+2. Slight possibility of no damage getting through, and up to 9 points. of injury, enough to bother nearly anyone given that comes right off Wounds. 

If you don’t want to roll dice, take the average Fixed Value instead of subtracting a die roll. That makes more armors kinda the same. As you can see, the method is a max protection of 2+Current AC bonus for Max Protection, and Fixed Value is Max Protect/2, rounded down. Round up if you’d like!

Parting Shot


I know I haven’t developed this fully yet, but it’s been a couple of days writing it, and I think the basic blocks are there.

Let’s look at a few example fighter builds.

  • The Commoner – All stats are 10, with no proficiency in aught but simple weaponry. We give him a spear, leather armor, and send him to die in drives. Pity.
  • The Beginning Swordsman – level 1 fighter looking at sword-and-boarding.
  • The Intermediate Great Axe Fighter – level 7 Champion with a two-handed axe and lots of ‘tude. I’ll add a level to my Level 6 Champion Fighter that I wrote up a while back.

The Commoner


Easy enough to do.

Wound Points: 10; Stress Points: 4; Defense Threshold: 10;  Shielding Threshold: 10; Wound Threshold: 12.

Threatening him with a sword at 1d20+5 (attack by a 1st-level character with a 1d8 weapon and STR/DEX 16) will result in an 80% probability that at least stress will be done, and 70% of that time it’ll go right past stress and hit the leather armor. Damage of 1d8+3 will meet armor of 1d4-1, doing 4-11 points of damage against 0-3 points of armor. Resultant wounds will be 1-11, An equal probability of 4-8 wounds means that the expected outcome of a single exchange is a foe who is either unconscious or dead. 10% of the time the foe will throw up a feeble parry, quickly exhausting his 4 Stress Points and still leaving him anywhere from terrified to risking death.

The Beginning Swordsman


Classic 1st level human fighter. STR 16 (+3), DEX 14 (+2), CON 15 (+2). 1d20+5 with a longsword, doing 1d8+3 damage (sound familiar?).

Issue: The Defense fighting style adds +1 to AC when wearing armor. Where does that go? Into DEX? Shielding? Proficiency? I’m going to put it in proficiency for now, assuming that this is using your skill effectively to ward off blows. 

Wound Points: 18; Stress Points: 12+20; Defense Threshold: 12;  Shielding Threshold: 16; Wound Threshold: 19.

Calculations: Wound Points are CON + STR bonus. Stress Points are 10 (basic start for fighter) +2 CON bonus) +20 (10 Stress x 2 proficiency from the shield). Defense Threshold is 10+2 (DEX). Shielding Threshold is 16 (12 Stress threshold +4 for the shield). Wound Threshold is 19 (Shielding threshold plus 2 for proficiency and +1 for Defense fighting style).

Threatening this one with his equal, there’s about a 35% chance of getting past his guard right to his armor, 15% chance of bypassing the shield and engaging the warrior directly, and the usual 20% chance of hitting the shield. The chain absorbs 2d4, so 4-11 points attack meet 2-8 on defense. One time in four, no damage will penetrate his armor.

Issue: OK, so shielding pushes off the Wounding threshold, which is good. But does it do anything else? I’m thinking it would be good to have shield strikes (above Defense, up to Shielding) cause damage to the shield itself, in addition to stress. Either tracking number of hits, or giving the shield an armor value itself. Both violate rules – my own rules. Book-keeping and added complexity. But if you want shield to be splintered, something like it will be necessary.


Great Axe Fighter, 7th Level Champion


Selecting two attribute increases for the purposes of simplicity, our 7th level fighter has +3 proficiency and STR 18, DEX 14, CON 16.

Wound Points: 20; Stress Points: 67; Defense Threshold: 12;  Shielding Threshold: 12; Wound Threshold: 16.

Here we see that there’s a big trade-off in leaving off the shield. +1 for Defense fighting style and +3 for Proficiency, but it still leaves a significant chance of simply striking home.

Issue: Well, this is a thing. There needs to be a way for a skilled fighter to mitigate, parry, defend or otherwise not just take it. Either taking double wounds as stress (a desperate defense), or a fighting style providing Stress Points would do it. 10 points x Proficiency (but no boost to shielding) would be depleted faster than that of a shield-wielding fighter – the lower Wounding Threshold relative to a shield-wielding fighter would cause defenders to choose the double-stress option more frequently. So less capable than a shield, but not nothing either. This would boost the Stress Points for this fighter to 97. 

The greataxe fighter with STR 18 does 1d12+4 for 5-16 points per hit, twice per turn, for 10-32 points of stress potential, striking on the attack at 1d20+7. 

Good and Bad, and Left Out


So I think the good here is that it’s still basically straightfoward and recognizably D&D. The concept of clean miss, stress, and wounds makes sense.

The bad news here is that while invoking double-stress to avoid wounds might be a solution to the problem, it seems too easy to bypass the defenses of a foe and strike his hide, especially for higher level fighters. It also seems like it might be just too easy to cause stress to begin with, but I don’t think so.

The narrowness of the proficiency bands suggest that something like double-proficiency might be done here (let’s ignore shields for a moment). Or even something like

  • All characters add Proficiency to their Defense Threshold
  • If you are fighting with a weapon or shield, you get your proficiency bonus with each weapon or shield you’re using.

So a fighter with +2 proficiency with sword and shield and DEX 14 (Defense Threshold 12) will add +2 for raw skill, +2 for sword, and +2 more for shield. That makes our first-level fighter with Defense Threshold 12 and Wounding Threshold 18. A fighter with +3 proficiency and the same kit is Defense Threshold 12, Wounding Threshold 21.  Sword and Dagger? That’s a defensible weapon in each hand, so same deal. Makes sword-and-board equivalent to two-weapons from a hit-probability perspective, but the additional stress you get from a shield will make it a bit better.

2-Handed Weapon fighters get the defensive shaft here, but get increased damage (but not a ton). Pick the right Feat and perhaps you can defend with them better.

So, not done. And the biggest challenge here will be tuning the process without invoking more than one or two special rules. You want something that goes easily at the table. Roll dice, compare to something simple, roll damage and/or armor, boom, done. 

But I’m not there yet, even if I think some of the concepts are workable.

The other question that needs to be asked is “are ranged weapons treated any differently?” The answer may well be – and should start out – as not just “no,” but “hell, no.” Don’t invoke special rules unless they’re needed. But I’ll think about it anyway.

The rules here preserve the core meaning of hit points as stress points. They allow bypassing or depleting stress so characters and players know when they’re bleeding, or when their tired. Healing surges and short rests would recover Stress, and I’d think that would be less contentious than if there’s a hint of “you sat down for an hour and your sucking chest wound is gone.” Things like Lay on Hands would be great for healing actual wounds, and thus truly miraculous. Healing potions could be distinguished between those that restore stress and those that restore wounds.

The stress points provided by shields and some weapons should be interpretable as an increased, but limited, store of resilience. And you know I’m going to suggest at some point that if you’re striking or shooting at someone caught flat-footed, and totally by surprise, that if you hit, damage comes right off of wounds (though armor would still be assessed). 

D&D5 provides a nice solid rules base for these explorations. But I do just enjoy playing the game straight-up, so when all is said and done, anything new accomplished here needs to be at least as good as what it replaces. Something of value must be provided. I’m not there yet . . . but as I noted, I don’t think it’s a forbidden destination.