One-die attack rolls

[Splarticus]

Inspired by Angry GM's article, "Acting on the Edge of your Seat," I've worked out a system for using a single d20 roll to determine both whether the attack hits or not, and also the damage the attack does. This way, the player knows immediately if they their attack landed or not, and also about how much damage they did. It's based on D&D attack rolls and damage, so I've kept the average damage within about 5% of plain old standard D&D rolls.

I use spreadsheets to calculate for the typical attacks for a character to give a distribution of how much damage they would do against an AC 15 opponent. For example, a level 1 fighter with a long sword and a 16 strength has +5 (+2 prof, +3 str) to hit, so he would hit an AC of 15 on a roll of 10.

His damage would be 1d8 +3. To determine his damage without rolling another die, I distributed the 8 rolls (more or less) between the range from 10 - 19, which are all non-critical hits, like this:

10~4,11~5,12~6,14~7,15~8,16~9,18~10,19~11,N20~12

So on a roll of 10, he does 4 points of damage, on a roll of 11, he does 5 points, and on a roll of 12 or 13, he does 6 points of damage, etc. On a natural 20, he does 12 points of damage , which is the average damage for 2d8 + 3.

The non-critical rolls are picked so that the average damage is 7.5, which is the same as the average damage for 1d8 + 3.

Bonuses and penalties to the attack roll, like Bless or Advantage, Disadvantage, these apply to the to-hit roll as normal. Although these can make a higher roll, it changes the average damage less than 5% or so. Bardic Inspiration for d8 or more will raise the average damage from a hit closer to 10%, but that's more rare than other effects.

For ACs other than 15, there is a modifier shared by everyone at the table to adjust to the 15 AC table. For example, for an AC 13 monster, all players would add 2 to the d20 roll, and then use the table as usual. For greater variations from AC 15, some of the bonuses are repeated, such as both AC 13 and 12 having a bonus of 2 to the die roll, to keep the damage within 5% of the normal system.

Advantages of this system is speed -- no need to do another roll to calculate damage, instant feedback -- one roll, and you not only know if you hit or not, but also how hard you hit, and simpler hit calculations -- everyone at the table adds the same bonus to the die roll.

Disadvantages are less dice rolling, more preparation time required to create combined to-hit damage tables for each PC, and the tables can be tricky to read until you get used to them. It cannot replace the standard D&D to-hit/damage system, since unusual attacks -- I throw my sword! I steal his Mace of Terror and hit him with it! -- cannot be prepared in advance. Also, monster attacks vary too greatly to be prepared in advance. Anyway, as DM I usually just use average damage for monsters.

Thoughts or comments? Would people be interested in using such a system?

[Grod_The_Giant]

This looks... way too complicated. Like you're trying to reinvent THAC0, only with the damage roll folded in somehow. Why not just use average damage values in place of weapon damage dice?

[MilkmanDanimal]

Why not just roll the damage dice at the same time as the to hit die? I don't see what you're gaining with this system other than a great deal of additional complexity.

[Mellack]

Not sure how this is simpler or faster. You have to still roll as normal. Then instead of rolling damage, you have to add or subtract from 15 depending on that creature's AC and then check the chart. I would also have to assume you would need a different chart for different weapons, at least for each different damage die. For example, what if that fighter with the longsword wants to swing with it two handed? Then with another attack decides to throw a javelin? And is there another chart for when you increase in your proficiency bonus or your stat increases?

[Knaight]

There's very good ways to handle one die attack rolls, but you're fundamentally fighting with the system here. There's some interesting properties that come from that (you do more damage on average to low AC enemies), but fundamentally this makes things more complicated. Had the system been designed around this from the beginning it would be a different matter.

[Arcangel4774]

One thing i like about this is the ability of armor to go from getting hit less often to taking less damage. However its much more complicated and would need to be worked for fighting styles feats and other abilities

[MaxWilson]

Advantages of this system is speed -- no need to do another roll to calculate damage, instant feedback -- one roll, and you not only know if you hit or not, but also how hard you hit, and simpler hit calculations -- everyone at the table adds the same bonus to the die roll.

Disadvantages are less dice rolling, more preparation time required to create combined to-hit damage tables for each PC, and the tables can be tricky to read until you get used to them. It cannot replace the standard D&D to-hit/damage system, since unusual attacks -- I throw my sword! I steal his Mace of Terror and hit him with it! -- cannot be prepared in advance. Also, monster attacks vary too greatly to be prepared in advance. Anyway, as DM I usually just use average damage for monsters.

Thoughts or comments? Would people be interested in using such a system?

As others have said above, the advantages of this system are not what you think they are (die roll + table lookup is not really faster or simpler than the status quo), and there are easier ways to gain the advantages you're looking for (roll two dice simultaneously). It's not that linking to-hit and damage doesn't potentially have some merit, but if you're doing that you should be doing for something that you won't get any other way, e.g. to increase the relative importance of armor by making AC correlate negatively with damage taken. If you were doing that, you'd also feel free to tinker with the system to make it easier to use at the same time, e.g. damage rolled = margin of success, up to a maximum determined by the weapon die, plus modifiers.

It is kind of interesting to think about that alternate system and how it makes greatswords far superior to daggers against zombies but almost identical against armored knights, and how it would affect the relative attractiveness of TWF, etc. But for the design goals you've actually articulated, I don't think moving to one roll + table lookup is actually the best way to achieve them.

[Splarticus]

Thanks for your feedback! Yes, my primary concern is that it's complicated. My hope is the benefit of having everyone on the same system, with same mod for AC, while using their own tables for their weapons, will make up for the complication. At my table, there are a lot of people looking at their bonuses and damage for each weapon, and I think having that pre-calculated may speed things up.

One thing this gains over using average damage or rolling damage dice at the same time as the to-hit, is adding differentiation between a hit with a 19 and a hit with a 12. The 19 is a high damage hit, even if not a critical. Bless feels like it directly increases your damage, not just makes a hit more likely. The one dice you roll matters, beyond determining hit or not.

@Mellack, different weapons would require different tables. On level up, or stat changes, I'll redo the tables. Minor changes can be handled within the system. For example, using a longsword two-handed raises the average damage by one point, so I'd just let that player add one to their damage when using the longsword with both hands.

Keeping it within the framework, probability, and damage specs of D&D definitely limits the new system. I'll be play testing it this week with my group. Wish me luck!

[Lunali]

This system may make higher rolls feel better, but it seems like it would lead to a lot of complexity depending on enemy AC relative to attack bonuses and any additional dice on the attack.

I'm currently playing a kensei monk, my rolled damage per attack could be d6, d8, d10, or even d8+d4. On a given turn I will almost always roll at least two different dice for damage. Additionally, I will use two different attack bonuses on most of my turns as my weapons give a bonus but my fists do not.

[Quoz]

I think the 2 mechanical aspects of what you are trying to accomplish - tying degree of success to outcome and streamlining to less dice rolls - don't necessarily work well together.

Most systems that I have seen that try what you are attempting use either dice pools - which give a bell curve probability instead of a straight line - or are much more rules light systems. 5th ed, with so much focus on bounded accuracy, is fairly fine tuned and any radical departure will require more patchwork fixes than is practical.

As stated above, even just straight martial combat can have a wide range of expected dice to be used even in single attacks. Sneak attack, two weapon fighting, superiority dice, ect. That's not even getting to magic, feats (not that I miss great weapon master or sharpshooter getting nerfed by tying accuracy to damage) and a whole host of other special cases.

I do think you're on to something with higher accuracy dealing better damage, but removing damage rolls is too far. Perhaps the option to replace or add one damage die with a larger die based on margin of success - 4 over AC adds a d4, 6 over a d6, ect. If you don't want it to just be a straight bonus maybe reduce base damage by 2 or add extra HP to the monsters.

[guachi]

I'd just roll damage with the attack roll.

It's faster.

[Splarticus]

@Lunali, d6, d8, and d10 each do an average of one hit point more than the previous. If the attack bonus was the same, I wouldn’t do different tables for those. Instead, use the d6 table, and add 1 damage for d8, and 2 damage for d10.

An extra d4 is trickier, since you can’t add 2.5 damage. If that were a common attack, I'd make a separate table for it. We have a ranger archer in our party, and I plan to make a table both for Hunter's Mark attacks and for attacks without it. Likewise for separate weapons that have different bonuses to hit -- I'd make a separate table. The goal is to have a useable table for 80-90% of the attacks. For any commonly used attacks, I'd make a table for that attack.

[Knaight]

I think the 2 mechanical aspects of what you are trying to accomplish - tying degree of success to outcome and streamlining to less dice rolls - don't necessarily work well together.
As a rule they can work pretty well - I'm just not seeing a good way to do it without some drastic overhauls to 5e's framework. There's a real possibility I'm just missing an obvious design space though.


I do think you're on to something with higher accuracy dealing better damage, but removing damage rolls is too far. Perhaps the option to replace or add one damage die with a larger die based on margin of success - 4 over AC adds a d4, 6 over a d6, ect. If you don't want it to just be a straight bonus maybe reduce base damage by 2 or add extra HP to the monsters.

A lot of systems do this in very elegant ways, they just don't tend to start with seperate roll systems and tweak them. For instance there's the opposed rolls in Fudge, where you add the margin of success to damage and subtract your opponent's armor to find how much you hurt them, or the three die system in Termination Shock, where the top two dice are added to see if you hit and the bottom die is damage, meaning that damage can never be more than half your attack roll.

That said, there are ways to shoehorn this. We could take a note from Burning Wheel, which has three specific damages available (glancing blow, normal hit, solid hit). Then we set those up with attack damage, at something like Avg/2, Avg, 3Avg/2, calculated in advance. Beating the AC by 0-5 is a glancing blow, beating it by 5-10 a normal hit, beating it by 10+ a solid hit. This still runs into some serious issues (Power Attack is kind of garbage now, any sort of reverse Power Attack is just ridiculous), but it's at least easier to calculate.

Similarly you could change the crit calculation, for a really rough and dirty way to do this. Beating AC by 10 could be a crit now, instead of rolling a 20. Things that change crit range adjust that number, probably by a little more than they currently do (beating it by 8 for a Champion Fighter, for instance).

[Man_Over_Game]

On that note, could roll 3d20, count the number of rolls that hit to determine how well you hit. Advantage lets you roll 4d20 and remove your lowest roll.

And while that makes attacks more interesting, it does add a lot more dice rolling into the game and slow it down, which is contrary to the OP's goal in the first place.

[KorvinStarmast]

I'd recommend not "fixing" something that isn't broken.

[Knaight]

I'd recommend not "fixing" something that isn't broken.

It's not broken per se, but it could easily be a piece of mechanics that rubs people the wrong way. That worse combatants that are easier to hit aren't any more likely to get hit hard can seem off, and it can be really frustrating when you're up against something that you're vastly better at fighting than and yet can't seem to deliver more than a scratch to them.

[KorvinStarmast]

It's not broken per se, but it could easily be a piece of mechanics that rubs people the wrong way. That worse combatants that are easier to hit aren't any more likely to get hit hard can seem off, and it can be really frustrating when you're up against something that you're vastly better at fighting than and yet can't seem to deliver more than a scratch to them. My pat response to this would be "the dice are fickle, it's a feature, not a bug" but I'll take that a step further. The team lead on this project writes the following:
The dice will be cruel to you, but you will soldier on
Preface, D&D 5e, 2014, Mike Mearls

So I'll go back to: don't try to fix what isn't broken. Accept the frustration as a natural feature of the d20 system.
This Isn't A Computer Game.

As a coda to this answer: my experiences from level 1-3 with Korvin Starmast, my original PC in D&D 5e, with the spell Suck Red Flame (uh, sorry, Sacred Flame) were an epic novel of frustration with either rolling a 1, 2, or 3 for damage or, the monsters dex saving versus my dc.

I didn't whine that the system didn't work, (yes, I cursed the dice roundly!) I soldiered on. What was kind of interesting to see, later in our 5e career, was that a tier 2 tempest cleric seemed to have more good fortune with that spell.

[Knaight]

My pat response to this would be "the dice are fickle, it's a feature, not a bug" but I'll take that a step further. The team lead on this project writes the following:
The dice will be cruel to you, but you will soldier on
Preface, D&D 5e, 2014, Mike Mearls
It's not a matter of the dice being cruel, but a matter of how that's implemented. The problem isn't that the output is bad for a character, the problem is that the output makes little sense in the simulation.

There's really no meaningful difference on the user end between a feature you dislike and a bug you dislike, and on the user end I can just pick other games or tweak this one, which I've consistently done.


So I'll go back to: don't try to fix what isn't broken. Accept the frustration as a natural feature of the d20 system.
This Isn't A Computer Game.
It's also not any number of other RPGs which don't have that particular quirk. On top of that, there are different kinds of frustration, and I'm much more inclined to accept "the dice are against me" than "the way the system operates produces stupid results in the setting fiction".

I softpedaled this earlier to be tactful, but as that's clearly out the window here, let me put it a different way. For a lot of people it's broken. What's being fixed is a genuine break.


As a coda to this answer: my experiences from level 1-3 with Korvin Starmast, my original PC in D&D 5e, with the spell Suck Red Flame (uh, sorry, Sacred Flame) were an epic novel of frustration with either rolling a 1, 2, or 3 for damage or, the monsters dex saving versus my dc.
That's largely irrelevant here, as it's a fundamentally different set of frustrations. A more analogous one would be how, because of how the system works, a deeply sluggish monster that can't dodge (starting with any genuinely immobile creature) somehow still manages to get hit no worse than someone actively dodging but not quite well enough. In an actual fight rolling with the strikes to minimize them is a thing, and here the simulation is coming up short on that in a very notable way. That may or may not be a thing a particular group cares about, but the attitude of "back in my day I walked uphill both ways and didn't complain about it" is useless from a design perspective.


I didn't whine that the system didn't work, (yes, I cursed the dice roundly!) I soldiered on. What was kind of interesting to see, later in our 5e career, was that a tier 2 tempest cleric seemed to have more good fortune with that spell.
Identifying a way a system doesn't work for you and changing it to make it work better isn't whining. Neither is identifying the ways a system doesn't work for you and using it to select a different system that works better.

[KorvinStarmast]

Identifying a way a system doesn't work for you and changing it to make it work better isn't whining. Neither is identifying the ways a system doesn't work for you and using it to select a different system that works better. The RNG system that d20 is based on is subject to the tyrrany of small numbers in each combat. DPR is meaningless in a given combat that lasts a few rounds.
Also, HP are not meat.
And yes, there are other systems. Playing them provides their own joys and frustrations. We live in a very fortunate time: the plethora of choices staggers the mind.

[Kane0]

Interesting, but complicated.
A single roll approach is totally feasible but there are a lot of factors in the system that youd need to tweak to accoubt for it.
I’d probably start with ‘roll to hit, excess is damage’ and work from there.

[Grod_The_Giant]

That said, there are ways to shoehorn this. We could take a note from Burning Wheel, which has three specific damages available (glancing blow, normal hit, solid hit). Then we set those up with attack damage, at something like Avg/2, Avg, 3Avg/2, calculated in advance. Beating the AC by 0-5 is a glancing blow, beating it by 5-10 a normal hit, beating it by 10+ a solid hit. This still runs into some serious issues (Power Attack is kind of garbage now, any sort of reverse Power Attack is just ridiculous), but it's at least easier to calculate.
Something along those lines is probably the best you'll get, though I'd go with something like "AC-5 as a glancing hit (no damage dice, just stat modifier) and AC+5 as a strong hit (extra damage die)." The d20 does not lend itself to "add the excess as bonus damage"-- with the expectation being that you hit on an 8 or above, you'd wind up with a 12 point spread. At 20th level, you could drop the stat to damage and have it roughly work, but that would be really swingy at low levels. Not to mention the slowdown of figuring out your margin of success each swing.

[qube]

@OP why not use the simplest of things and just substract?
roll 1d20 (+mods). if you equal or beat the AC, you do damage equal to the difference plus your strength mod.
on a natural 20, add twice your mod (instead of rolling the dice twice)
+5vs AC 15, +3 strength with a d10 weapon, gave 4.525; while under this system it's 4.550
weapons with different weapon die, now instead change the damage mod and/or attack bonus. For example
a sword in 1 hand only allows you to use the power of 1 arm, ergo damge mod -1 (3.95 vs old 3.9 DPS) )
under the two hander,s a maul could be described to use momentem to incread the blow: -1 attack, but +2 damage (5.5 dps), while a greatsword could have or +1 damage & high crit (ad your mod a third time on crit) (5.35 dps, which is equal to the old school 2d6+str dps)

[Splarticus]

First play test of system done!

Used this 1Die system with a gaming group over the holidays -- four days of continuous gaming. They made new characters, so it took a little while to get the system set up for all of them.

Once they all had their 1Die strings, things went smoothly. Nice that all the individual to-hit and damages were baked into their 1Die string, and mostly all they needed to know what was the modifier was for the AC of the opponent, which they all shared. I had prepared little AC cards for all common ACs that I hung over the DM screen.

The roughest adaptation was the two-handed weapon fighter. Changed the "N20" notation for natural 20's to "Crt", to accommodate her Improved Critical ability. Also, had to calculate the effective damage for the Fighter Great Weapon Fighting style, for the re-roll ones or twos bit. Figured out the average great sword damage was 8.33 (as opposed to 7 without the style), and then reverse calculated that into rolling a 1d8 + 1d7, for an average damage of 8.5, within 3% of original damage. (Nice thing about spreadsheets -- no problem calculating a seven-sided die roll.)

Feedback was largely positive. One player mourned the loss of rolling more dice. Most were ok with it and felt it was faster.

Next step is to test with my regular gaming group.