Hit Points replaced with ‘Usage Dice’ ?

image_previewPDF version here with UD tables (it’s PWYW just in case you want to encourage such tomfoolery)

EDIT – the below paragraph is just to pick up on some FAQ/comments/feedback:
:: the UD roll replaces the damage roll – so there is no net increase in dice rolling
:: Yes, to reflect combat the UD target number is dependent on your PC’s class and level
:: the UD target number changing with level is no biggie – HPs change with level too
:: it’s not very complex, you just replace ‘Max HP’ and ‘Actual HP’ boxes with UD boxes
:: Agreed, UD and HPs are not ‘realistic’, they are just game mechanics
:: This is still a thought experiment so work is still needed (see healing and monsters)
:: Some people think UD requires more bookkeeping – I find this an odd conclusion 
:: IMO drama is at the heart of UD, it makes each hit a meaningful threat to PC life
:: Some people don’t like Usage Dice (UD) mechanic, and they never will

Usage Dice (UD)
As I understand it, in the Black Hack you don’t track things like individual arrows. Instead, you use a ‘usage dice’ (UD). At the end of the relevant turn, you roll the UD: if you fail, you move down one UD, otherwise you keep the same/current UD.

So, if the UD is a D10 and you fail you move down to a UD = D8. This is repeated until you get to a D(minimum) e.g. D4. A fail on the D(minimum) means that the “resource” is used up.

Applying this to Hit Points
Why – who wants to track pesky Hit Points (HPs) anyway …?

More seriously, the thing that is most ‘fun’ (IMO) about UD is the uncertainty of when the ‘resource’ will expire. Adds a dash of tension.

Hopefully, it makes wounds more significant and so meaningful …

This idea tries to address these points. So:

  • No tracking individual HPs
  • Tension – will the PC progress a significant step to death on a successful hit
  • Each wound is significant; PCs of the same level can take the same number of significant wounds before death (except high level fighters and clerics, who I’ve given a bonus ‘fortitude D2 usage die’ to – think Boromir peppered with arrows and fighting on)

… and I also hope this would make combat a more scary option for players

The below table gives the UD and target number for each PC by class and level:

HP Usage Dice Table

This is so under/overpowered right?
Hopefully I’ve not screwed any of the maths up! Spreadsheets can go wrong!

I compared this UD system with HPs in AD&D for the classes over the levels.

Base-line: To do this, I worked out average HPs a PC would have based on HPs if rolled i.e. rules as written (RAW.HP)

I then brute force modeled in Excel (1000 runs) out how many successful ‘hits’ on average  would be needed to reduce a PC to death using this UD system, awarded 3.5 HPs per damaging hit (i.e. mimicking a DA=D6).

For example – a first level fighter has a D4 UD and needs 3+ to avoid damage (50;50). But if they pass they get another go. In theory they could avoid damage from 10 successive hits (but the probability is low). So I needed to add up all the little pieces.

Anyway … I basically worked out how many hits a PC would be able to take on average (over 1000 runs) and compared this to how many hits a ‘standard’ AD&D character (of the same class, with ‘average’ HPs, taking ‘average’ damage) could take:

Usage die for HP vs Normal HPs - how many hits can you take on average

If I’ve not made any mistakes … (???) … then this UD method is not far off the standard HP method on average.  There are a few blips, but no system is perfect.

So, other than having stark and unsettling jumps towards death, the UD system appears to track well enough to AD&D (on average).

In case anyone is interested, this is effectively the same sort of thing, but expressed as % compared to the AD&D base:

percentage of base

Small differences in ‘hit’s are magnified as % at lower levels.

Example of UD combat?
Belorgt is a 7th level fighter and is unwounded, so  use UD = D8, and to avert damage from a hitting blow they need to roll 6+ on the UD8.

So, a roll of 8 means the hitting blow is averted; so keep the same UD (6 : UD8)

However, a roll of 3 would mean a significant wound was received and they would move down one UD. They would now use UD of D6 and need 4+.

Another hit means the UD goes down to a D4, needing a 2+ to avoid a hitting blow.  Man, this is a bad day, it’s a 1! For a thief or magic-user this would be the end!

But, thankfully, Belorgt has deep reserves and can fight on despite 3 nasty wounds – however from now on it’s 50:50 if they get another blow!  The bonus ‘fortitude UD’ is a D2 and Belorgt needs a 2 every time (or an even roll)! The next failure means: incapacitation, mortally wounded, or death etc.

These PCs are too squishy
You’ve modeled against RAW HPs – I normally give PC extra HPs, and what about CON bonuses etc. Maybe just bump the UD up one level, so treat a 3rd Lv fighter as a 4th level fighter on the tables above etc.

Other things that I have not really thought through ….

Perhaps progress as Fighters where HD = Lv
Or, as guidance on a UD monster system: adding more UD means they can take more wounds before death, lowering the target numbers makes them tougher.

Powerful attacks (e.g. breath weapons)
A fireball doing 6D6 might be considered 6 successful attacks each needing a UD save.
A giant’s tree club doing 2-12 = 2 successful hits, each needing a UD save?

Hrmmm …each ‘HD’ worth of healing restores one UD? I think that is probably too easy to revert the much larger effect of dropping down a usage die.

Or, perhaps better  – wounded PCs need to roll against current UD: a fail (I say fail because this reflects the symmetry of going up or down the UD from the current health position) and they jump back to the previous UD so a UD D4 jumps to a UD D6 etc. So if the UD is a D6 with a target of 5+, a roll of 1-4 from that position represents a change in the UD – so with healing it goes up one UD to a D8, and for a wound the UD goes down to a D4.

Perhaps, with a fail, as a consolation, the target number on the current UD is lowered by 1, e.g. so a 4+ on UD6 goes to a 3+ on UD6. So, this mimics powerful and milder healing.

Some damage wearing?
I’ve not done the maths  – but I suppose the target number could be eroded every time a successful hit is saved, but never more than the maximum number of the UD. So if the target number is 6+ on UD8 and a hit is made and a save is made using the UD, then the new target number becomes 7+ on UD8, if this happens again it’s 8 on UD8, if this happens again it remains 8 on UD8. A fail of course reverts to the UD6.

Levels 11+
I ran out of energy for those, but I see a D10 coming into play!

Constitution bonus
Option 1 – add the D2 UD bonus on at Lv1
Option 2  (which I prefer) – give the PC 1 or 2 ‘CON points’ to spend between full healing, the points can be ‘spent’ to nudge a just wound (fail) roll into a pass roll. So if you need a 4 on a D6 to avoid a wound and you roll a 3 you can spend a CON point to nudge the roll to a 4.

That’s it.

– – –

Me on DriveThruDriveThru; at the moment I’m mainly pimping my procedural:
:: High Seas ‘Hex Crawl’ – In the Heart of the Sea,
:: Wilderness Hex Crawl – In the Heart of the Unknown,
:: Dungeon/network generator – In the Heart of the Delve & Dangerous

8 thoughts on “Hit Points replaced with ‘Usage Dice’ ?

  1. ClericsWearRingmail

    I really like this. I’m not typically a fan of usage dice, but – where Tim Kask can be paraphrased saying that HP doesn’t necessarily reflect meat points and that damage to HP doesn’t equate to wounds, but instead the erosion of luck, stamina, etc. leading to a telling blow – this system, I think, represents that abstraction better: the probabilities are the same or similar, but it puts dice in the hands of the players, giving them a sense of active defense and ownership, and also keeps class and level relevant.

    Good read. I may have to come back not on mobile to get a better view of the charts and tables.

    Liked by 1 person

  2. emarsk

    It’s an interesting idea, and if you like it, you like it. But:

    > No tracking individual HPs

    But you’re tracking a die type AND a target number. There’s even more info to track: you substitute one piece of information with two. Additionally, now you have to reach to a different die every time you’re “injured”. And with your proposal on healing and damage wearing, you’d also have to track target numbers.

    > Tension – will the PC progress a significant step to death on a successful hit

    If I understand your procedure correctly, you’re substituting the damage roll with this hit roll. Again, there is very little functional difference between the two: both introduce uncertainty about how quickly your health is diminishing. The significant differences I see are:

    – No differentiation in attack effectiveness (a rat bite is the same as a golem punch). This could be re-introduced, but it would complicate the mechanics. As it is, what determines the rate of failure is entirely on the victim side.
    – The chance of losing health generally slows down the more “injured” you are.
    – There’s always a significant chance of the roll saying “nothing happens”, which is something I don’t like very much: I prefer systems where every time dice are rolled, there’s some sort of consequence.

    > Each wound is significant

    I don’t get what you mean here, and how is this different than having traditional HPs, unless you associate some penalties to the die types (and you can do a similar thing with traditional HPs or stress tracks anyway). If I want “hits” to count as significant wounds, I use something with mechanical and diegetic consequences (like conditions/tags).


    1. Goblin's Henchman Post author

      Hi @emarsk

      Reading between the lines, I think this kind of system is not your cup of tea. I think (dare I presume) you like to see it all playing out in a smooth regular, dare I say, predictable way … like to know where you stand and where it is going: ‘that shot did 5HPs of damage to the fighter who now has 67 HPs left’. Rinse. Repeat.

      And to be fair, this system wasn’t written with someone like that in mind (even if that is not you). This system is merely an option for those that might like it. People who like UD think they are simple to use (once they are understood).

      To address your specific comments (a lot to break down here):

      :: Accounting – There is still some bean counting to do (it’s in all systems). In this case the PC simply needs to add the UD target numbers for their class to their character sheet – replacing the ‘Actual’ and ‘Max HP’ box (you’ll note that the target numbers lock in when the PC adds a new UD size). Then the rubber and pencil are obsolete for HP tracking. Players just need to know which dice they are on

      :: Tension – the difference is the high variability in the UD system. With HPs damage is mostly a steady incline plane leading to death. UD has sudden *unpredictable* lurches towards death. Also, with the UD system a 1st level PC can unexpectedly survive 10 successive hits (with luck) – this kind of drama is not possible with standard HPs.

      – Not quite, I did say that 2-12 would count as two standard hits etc.

      – rat bite to the jugular might be more deadly than a knick on the arm with a sword

      – HPs have been talked around in circles for an age for lacking “realism”. HPs is just a way to alot ‘life’. In some ways, I think this UD system is more “realistic” than HPS. Generally, a fighter, cleric, thief and MU (of the same level) take the same amounts of significant hits before death, but the fighter tends to avoid those significant hits. You could argue that as the fight progresses the PC is getting down to defending their lives and now things are getting serious. HPs damage is certainly not index to the amount of damaged taken – one minute the fighter up ( hitting 3 hit per round full bore) and the next she’s dead.

      – Nothing happens – well this happens in all RPGs: “Roll to hit. You miss”. I wouldn’t say nothing happened. The exception, perhaps electric bastion land (into the odd), where there is always damage in fights. With UD, something is happening (aside from the drama and the player experience) when you are hit, it’s just not significantly worth changing the UD. For example, I’d say marking your HPs from 95 to 90 is not very noteworthy, barely anything has happened.

      – Significant – a loss of 5HPs to a 10th level fighter is not ‘significant’, it’s barely worth lifting the pencil, paper and rubber for. But, a 10th level fighter dropping a UD is significant – the PC has lurched a significant way towards death. Therefore, the UD rolls always matter, it’s not just another roll of D6 damage.

      Thanks for your comments. In part this post is a thought experiment and is not intended to replace all other ‘life’ systems. I’ve nothing against HPs, I’m rather fond of them.

      Hopefully … I have replied to all/most of your observations!?


      PS Did you know some people actually like lemon curd !?


      1. emarsk

        > Reading between the lines

        That’s unnecessary, and you presume wrong by the way: I hate “Rinse. Repeat.” mechanics. My comments were aimed directly at the mechanics in relation to their proclaimed features, not your – or my – preferences, or even the mechanics per se (which are fine, to be honest).

        The only preference I expressed is to have rolls do something, one way or the other. That’s why I like contested combat rolls: both sides roll (or just the player, in case of a player-facing system), the winning side deals damage / stress / whatever, with no separate attack and defence phases.

        > with the UD system a 1st level PC can unexpectedly survive 10 successive hits (with luck)

        The roll to hit already does that.

        Since with UD a “hit” can have no consequences (you’re not modelling taking wounds), it becomes just another ineffective attack. In practice, you have 3 or 4 HPs, two consecutive rolls to hit (with an – obviously – increased combined chance of failure), and a fixed damage of 1.

        > this UD system is more “realistic”

        In reality, a single hit can kill you. Or you can survive several hits, but you’d still be injured, and for a long time, maybe even the rest of your life. Neither UD nor HPs model that.

        Complications / conditions / consequences (like in Fate, Cortex, PbtA, FitD) can be a more realistic approach, if that’s the goal, and they could be implemented alone or on top of UD or HPs / stress tracks.

        > Nothing happens – well this happens in all RPGs: “Roll to hit. You miss”.

        That’s not true. “Roll to hit. You miss” is just one of the many possible mechanics to model a combat. There are many RPGs where “nothing happens” is minimised, or even completely avoided. You gave two good examples yourself, but there are plenty more (PbtA, Genesys, Cortex, PDQ, FitD).

        Also, I say “nothing happens” in terms of meaningful outcomes that change the situation. Sure, you can describe a furious bout where both opponents – despite their prowess – aren’t able to land a good hit, but that’s not what I mean here.

        Also also, I don’t mind a single potentially ineffective roll (although I still prefer when games “fail forward”), but two in a row (to hit + UD) seem a bit pointless to me. But I’m not pretending there’s a “right” or “wrong” here, it’s just my preference.

        > marking your HPs from 95 to 90 is not very noteworthy

        The problem here is HP inflation, not HPs per se. Not all HP-based games have that issue. You assume huge amounts of HPs (67, 90, 95!). Try 6 (or even less), and see how scary combat can be. One (un)lucky damage roll and you’re down.

        > Did you know some people actually like lemon curd !?

        I do. I like lots of flavours. 😛


      2. Goblin's Henchman Post author

        Hi @emarsk

        Thanks for your reply. This thread is getting long so I’ll just jump to my comments in reply:

        :: Out of interest do you like, and/or use UD in your games?

        :: I’d say not quite, you’re talking about surviving infinite misses, which of course is possible in all games. In reality, this HP UD is more of a ‘saving throw’ vs an actual hit. In something like Warhammer you have a ‘to hit’ roll, a ‘to wound’ roll and then the actual wounds. This UD mechanic is more like that I suppose – roll ‘to hit’, then roll to see if it is a ‘significant wound’, then take a significant “wound” (which means death, or moving down a UD).

        :: In reality, HPs do not model wounds either (no human can take 10 gut shots with a sword and shake it off), to paraphrase Tim Kask (see poster above): HPs doesn’t necessarily reflect meat points and that damage to HP doesn’t equate to wounds, but instead the erosion of luck, stamina. UD in effect is the same thing, just this ‘wear’ is not iteratively quantified – dare I say it, it’s almost more a quantum state. Your PC is “wounded”, and they are in a state somewhere between UD(x) and UD(x-1), but in the game we are not going to worry where exactly you are on that trajectory.

        :: We both agree that UD and HPs are not ‘realistic’ they are simply ways to ‘game’ a fight where the combatants may be more resilient than others (hero vs a peasant). It’s a fantasy game.

        :: I don’t disagree there a different ways to run combat, and everyone is free to choose the system they like. This is just one of those options which a person could choose.

        :: I don’t think two passes on a UD roll is pointless, it’s two points of drama, each of which *could* have significant consequences for the PC. It’s like passing two rounds of ‘Russian Roulette’ and saying, that was pointless. In this HP UD system, for a low level PC a failed UD roll is death; for a medium level PC it means one pip from death, and for a mega PC (which I don’t like) it’s 1/3 or 1/4 of the way from death.

        :: That is part of the point here – it’s to make fighting more dramatic and scary. It’s not until 5th level that any PC can be *sure* of surviving two standard hits. I’m a fan of low level games, and you will note that the PC at level 1 are one wound from death.

        I don’t like higher level games, but other people do, hence the expansion of the table to Lv 10.

        Thanks for the comments.

        In the end, the big picture here is that this is a system for someone that likes the idea of UD to track HPs.

        Lemon curd fancier … and I thought me were going to get along!



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