Damage Roll as Attack Bonus

Need to write something to stay in the habit. Story's going well, just trying to avoid burnout.

There are three separate "problems" I have: making attack and damage rolls separate per se is tedious; attack bonuses are tedious to track separately and can also be confusing, e.g., about whether you also add them to damage rolls; and the set of classic armor class values {10, 12, 14, 16} represents very low probabilities if you assume a typical modifier of 0.

How about you use your damage roll as your attack bonus? Meaning:

 D20 + D(Weapon) ≥ AC

We would get probabilities as follows (notice that each die step adds ~5%):

Damage AC 10 AC 12 AC 14 AC 16
d4 68% 58% 48% 38%
d6 73% 63% 53% 43%
d8 78% 68% 58% 48%
d10 82% 73% 63% 53%
d12 85% 77% 68% 58%

Speeds things up in terms of hitting more often and also treating attack and damage rolls as a singular operation rather than two discrete steps of a procedure (even if you opt to roll the two dice together). Combine this with the rule from my friend Nova's Advanced Fantasy Dungeons that damage rolls correspond to initiative rolls (lower is better), and you've more or less translated the Chainmail weapons table into a more abstract format without additional numbers.

This also makes class-based weapon restrictions more intuitive, I think, since in designating them you're also setting the potential range of attack probabilities. You could also give each general type of weapon a special critical effect as per Bob the World Builder, although I think his conditions (natural 20 and roll 8+ on damage dice) are too strict. Maybe on a 20+: slashing weapons auto-hit an adjacent creature for the same damage; smashing weapons knock the target prone; and piercing weapons deal exhaustion; or you forgo the weapon-specific effect and just get another action.

I'd like to thank Simone de Beauvoir for showing me the potential of stacking multiple colons and semi-colons in a single sentence: it really helps to sort of communicate the vibes of where a sentence is going; it also is very fun if you try it out.


  1. Oh. Every time I think I've seen every variation of the idea, someone comes up with something genius. I like that a lot.

  2. If you used your damage roll as an attack bonus you could add anything above and beyond what you needed to hit to your damage.

  3. Cool. The attack/damage roll works like this in Monsters & Magic by Sarah Newton: 3d6 + 1dx ≥ AC.

  4. Two fun corollaries to this idea:

    1. If I recall correctly, the D&D Next playtest used a proficiency die (rather than flat modifier), and that variant remains as an optional rule in D&D 5E. You could use that, and read the proficiency die as the damage roll as well. Akin to the venerable "all weapons do d6" but now scaling with level (I'd intuitively roll the proficiency die "with advantage" for 2H or TWF, but haven't checked the math). Would work fine with old-school HP/HD, but probably want to reduce first level HP a touch in D&D 5e.

    2. Use the popular NSR rule of damage die = class HD, so your Magic-User gets +d4 attack and damage while your Fighter gets +d8. This would very nicely further differentiate the classes from 1st level without the indirection of weapon proficiency and the equipment list (something I find new players trip up on, and frankly doesn't add enough for even experienced players in my opinion). When they would increment attack per OD&D (per 3, 4, or 5 levels) could just step the die to next size up in chain.

    Always enjoying some rules-noodling.


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