Changing The Way You Crit

This is one of the recent changes that I’ve made to my campaign that just plain works well and makes sense. The way we used to crit in D&D was based on the natural 20 roll, and dealt double damage. That’s just how we’ve always done it. 20 hits anything, always does double damage. It gave you a 1 in 20 chance to make for a badass play. However, a guaranteed hit with double damage only feels good when you get a decent damage roll on it. It’s always been a weird feeling when you roll that nat 20, then follow-up with a minimal damage roll to double. I’ve never liked that feeling, it was a waste. That 1 in 20 chance just blown by a crap damage roll.

There’s ways to get around it. I’ve played with a DM who liked to add an extra d6 die for critical damage, at least guaranteeing an extra 1pt of damage on your normal roll, but that still allowed to chance to screw over a good crit as well. I’ve also played where crit hits were rolled on a separate chart to figure in locational damage, lopping off an arm or a finger, puncturing an internal organ and such. Those are really kind of harsh when you throw it at a player.  All fun and games until the shoe is on the other foot.

There’s a handful of examples from videogames that do away with any variation on crit rolls as well, adding a flat % of damage to your normal attack damage. I find these far less interesting as a tabletop rule. People like rolling their dice, people like rolling lots of dice, counting them up, and have pride in big numbers. It’s just how we roll.

My current, and relatively ingenious, method of doing critical damage totally forgoes the to-hit roll. We’ve separated the critical strike (natural 20) and the critical damage (max weapon damage) from each other. The natural 20 roll is still effective in penetrating defenses, hitting a weak spot, and allowing you to roll damage by getting in that perfect hit. It’s also still affected by things that would modify your natural crit range to a 19-20 or 18-20 depending on the ruleset. Yeah, you miss out on the instant double damage, but what you give up in doubling, comes back to you on the critical damage chance.

This is the good part. Instead of doing flat double damage or adding another die of damage, my critical damage attacks incur anytime a player deals within 90% of their max weapon damage. For a weapon that deals 2d4, they have to roll two 4’s, and would be allowed to roll their weapon damage a second time. Normal damage would have a range of 2-8, wheras crit damage would have a range of 10-16. This changes slightly when your base weapon damage is higher than 10, for example. A weapon dealing 1d12 would crit on a roll of 11 or 12, normal damage being 1-12, crit damage being 12-24.

This is also taking into consideration that damage being dealt is at the standard x2. For x3 crit damage you would add another set of weapon damage. 2d4 x3 crit would have a range of 12-24. 1d12 x3 crit would have a range of 14-36. This makes higher multipliers on damage more feasible without scaling dramatically out of control by allowing the range to grow on them, while still dealing a significant low range of damage.

An additional caveat that I’m considering is allowing magical weapons to add their bonus to the weapon damage roll, effectively giving magical weapons a greater chance to do crit damage with every successful strike. I feel like this could potentially add a lot more in the way of crit rolls which, on the fantastical side of things, reflects how powerful these items really are. Being that we just started new characters, I haven’t had much of a chance to test this out.

Now, if you’re following along with the math involved here, there’s going to be a lot more crits going on. I’m aware of that. Whereas before the chance to crit was 5% (1 in 20), the current chance to crit is much higher. A quick breakdown!

  • 1d3 – 33% crit chance – 4-6 crit damage range
  • 1d4 – 25% crit chance – 5-8 crit damage range
  • 1d6 – 16.5% crit chance – 7-12 crit damage range
  • 1d8 – 12.5% crit chance – 9-16 crit damage range
  • 2d4 – 6.25% crit chance – 10-16 crit damage range
  • 1d10 – 10% crit chance – 11-20 crit damage range
  • 1d12 – 16.5% crit chance – 13-24 crit damage range
  • 2d6 – 5.5% crit chance – 14-24 crit damage range
  • 3d4 – 4.7% crit chance – 15-24 crit damage range
  • 2d8 – 3.1% crit chance – 18-32 crit damage range
  • 3d6 – 1.4% crit chance – 21-36 crit damage range
  • 2d10 – 3% crit chance – 22-40 crit damage range
  • 2d12 – 2.1% crit chance – 26-48 crit damage range
  • 3d8 – 1.2% crit chance – 27-48 crit damage range

Yeah, those are interesting numbers. Something to consider, rolling multiple dice weighs you heavier toward the average, the more die you roll, the closer to the average you’ll be. In these instances you’re giving up a high crit rate for a more stable average rate. It also means your average crit would be much higher than an equivalent max damage crit.


Way more interesting than the natural 20 crit rules, imho.


4 thoughts on “Changing The Way You Crit

  1. D&D 4e handles Nat20 crits as doing max damage, then +1d6 per enhancement bonus of a magic weapon. As you said people do like to roll dice. Have you considered maxing the 1st damage roll and then rolling the others?


    A 2d4 weapon with a x2 Crit damage would do the normal 8 (2d4) + Ability Mod damage then roll the next 2d4 weapon damage to add on top.


    • We’re backing away from the Nat20 as a damage mechanic so I can adapt it for more interesting spot-play. Instead of it being a multiplicative damage boost in most aspects, I’d like to make it a chance for a PC to pull off some maneuver they wouldn’t normally attempt. Make it more like a free called-shot they can pick out after the roll. You can do a lot of interesting things with a called shot, and they don’t necessarily need to have damage involved.

      I imagine during combat characters are looking for ways to get an edge. The Nat20 has long served us as that sudden edge in battle, but only in brute force terms. Pushing the brute force down to the mercy of the damage roll where it fits more appropriately opens up the chance to hit for spontaneous creativity, or maybe a signature move thought up on the fly. That 5% chance you have during a fight to just pull off something crazy, or an opportune opening in your opponents defenses to exploit an exposed weakness.


      • Two things I notice when I parse the numbers on this.

        One is that you have significantly improved the average damage of small weapons.

        Second is that double dice rolls now have a boost in average damage over their single die counterparts, which was not there before.

        Neither of those is necessarily “good” or “bad” in my book, just different.


Bother With A Comment

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s