Exploding damage dice in 5E

[Malifice]

Whats peoples thoughts on playing a game where all damage dice 'explode'?

As in 'if the result of any damage dice results in the highest value of that dice, it is rolled again and added to the total.'

Meaning a single dagger thrust could kill, and big falls and breath weapons are positively scary.

Any unforseen consequences? It boost GWS a fair bit ((re-rolling 1 and 2 on a d6 is pretty potent when 6's also explode).

Pros: Makes combat a bit more deadly, and unpredictable.

Cons: Makes combat a bit more deadly, and unpredictable.

[Knaight]

Any unforseen consequences? It boost GWS a fair bit ((re-rolling 1 and 2 on a d6 is pretty potent when 6's also explode).

This makes low die attacking generally better, but absent GWS or similar mechanics an increase in die size is always an increase in average damage. With GWS, not so much. A quick pseudo table:
[Die Size]/[Explosion Probability]/[Expected Explosions]/[Damage Per Explosion]/[Average Damage]
(d3, 1, infinite, 3, infinite)
(d4, 1/2, 1, 4, 7.5)
(d6, 1/4, 1/3, 6, 6.5)
(d8, 1/6, 1/5, 8, 7.1)
(d10, 1/8, 1/7, 10, 7.875)
(d12, 1/11, 1/10, 12, 8.7)

So d3 weapons basically bring back the d2 crusader, then d4 weapons are suddenly really good, to the point of actually being stronger than d6 or d8 weapons on average. The probability distribution there is weird.

This is part of general imbalance where low die options just generally get nastier.

[Malifice]

This makes low die attacking generally better, but absent GWS or similar mechanics an increase in die size is always an increase in average damage. With GWS, not so much. A quick pseudo table:
[Die Size]/[Explosion Probability]/[Expected Explosions]/[Damage Per Explosion]/[Average Damage]
(d3, 1, infinite, 3, infinite)
(d4, 1/2, 1, 4, 7.5)
(d6, 1/4, 1/3, 6, 6.5)
(d8, 1/6, 1/5, 8, 7.1)
(d10, 1/8, 1/7, 10, 7.875)
(d12, 1/11, 1/10, 12, 8.7)

So d3 weapons basically bring back the d2 crusader, then d4 weapons are suddenly really good, to the point of actually being stronger than d6 or d8 weapons on average. The probability distribution there is weird.

This is part of general imbalance where low die options just generally get nastier.

There are no d3's that Im aware of in 5E.

D4 is as low as it gets right?

Also; there are no d4 heavy weapons (barring allowing PAM's bonus action 'pole'strike to benefit from GWS, but that's a little iffy)

[Knaight]

There are no d3's that Im aware of in 5E.

D4 is as low as it gets right?

In current releases, yes. The d4 to d6 shift is a fair bit weirder, but I don't think there are any d4 options that qualify for GWS anyways.

[Malifice]

In current releases, yes. The d4 to d6 shift is a fair bit weirder, but I don't think there are any d4 options that qualify for GWS anyways.

See above; just edited my post.

PAM's off hand bonus action pole strike is technically a d4 damage attack that benefits from GWS.

(I personally rule the pole strike doesnt qualify for GWS/ GWM in my games)

[JBPuffin]

Wait a minute...GWS quarterstaff fighting...I know my next character!

[Malifice]

Anywhere else it might skew?

Im thinking of spells that deal 1d4 (with re-rolls; like from empower spell). That has a cap on re-rolls so it should be too bad.

[LeonBH]

Chaos Bolt will potentially get a powerful buff since it ricochets if the d8's are rolled the same.

[Cespenar]

Meaning a single dagger thrust could kill, and big falls and breath weapons are positively scary.

If you want these effects, I'd rather suggest a simple Coup de Grace mechanic, coupled by a Massive Damage Threshold mechanic.

Adding even more dice swinginess to the already chaotic 5e combat isn't a very good idea, IMO.

Possible thresholds:

-Single damage over Con score: roll Con save or gain 1 exhaustion.
-Single damage over twice Con score: roll Con save or fall to 0 HP.

[Kane0]

Rogues. Rogues everywhere.

But for the most part, sounds like a fun idea. Probably only sign up if you dont mind lethal surprises though.

Edit: and many fireballs. Wherever you find fistfuls of d6s really.

[LordNibbler]

D&D already has an extra damage trick, the critical hit. In Savage Worlds, the exploding die works because there is only one die for damage and no other mechanism for extra damage on a good roll.

[Aelyn]

D&D already has an extra damage trick, the critical hit. In Savage Worlds, the exploding die works because there is only one die for damage and no other mechanism for extra damage on a good roll.
Actually, SW has "Raises", which is where you exceed the target number by at least 4. On a raise with an attack, you deal an extra d6 damage - and given both the damage explosion mechanic and the way damage works in SW, an extra d6 is more significant than you might think. Even without exploding dice, the raise system would allow for great rolls to get extra damage.

[Ivor_The_Mad]

I actually real like this idea. I think ill try this out to see if its op, if not i might add it to my house rules. The only problem i see is if you keep rolling 4 on a d4 and end up dealing like 36 damage at first level. Also would the modifier only count once ?

[PrismCat21]

I actually real like this idea. I think ill try this out to see if its op, if not i might add it to my house rules. The only problem i see is if you keep rolling 4 on a d4 and end up dealing like 36 damage at first level. Also would the modifier only count once ?

If exploding dice were in play, I'd only allow one 'explosion' per attack. No 36 damage on a d4, at most an 8.

[strangebloke]

1d4 averages 2.5. With explosions, it would average something like 3.2. So average DPR wouldn't be completely dominated by this.

Getting multiple explosions on one die is pretty improbable, but when it happens... yikes. 1/16 chance to roll a 4+4+1d4 on a 1d4 for an average of 10.5 before modifiers. GWF becomes absurdly good.

Overall, though, not a fan. Requires way more re-rolls which slows the game way down. Like, you're a vPally with a greatsword and you're dealing 2d6 + 1d8 + 1d6 + 5d8... and then you crit... and you have GWF....

By my count that is 18 dice without GWF or explosions, an average of five rerolls from GWF, and somewhere around 3-4 explosions (which will result in 1 more GWF trigger and 1 more explosion) That's 29 dice rolled in a single attack action. I'm not even counting crusader's mantle, etc.

What is this, exalted?

[Rhedyn]

I rolled an 8d6 fireball in an exploding dice roller 25 times and got an Average of 31.5 with a high of 54 and a low of 20.

(I did not calculate variance or standard deviation)

[Ivor_The_Mad]

If exploding dice were in play, I'd only allow one 'explosion' per attack. No 36 damage on a d4, at most an 8.

Ok thats a lot better. On a crit where you roll 2d6 and you roll 2 6s do you roll twice more or just once.

[Aelyn]

Exploding dice increase the expected value of a given roll by a factor of (x+1/x), so an exploding d4 (normally EV 2.5) goes to EV 3.125.

The factor is the same no matter how many dice you roll, so a standard fireball does 8d6 for an EV of 28, but an exploding fireball (heh) does (7/6)*28 = 32.7 on average. Of course, it also has higher variance, and I can't say how much that would change.

EDIT: This means that the more the dice effect the end result, the bigger the effect of exploding dice; similarly, smaller dice sizes benefit more from exploding. Magic Missile loves the idea of exploding damage.

[MrStabby]

A few other things:

Monks, already strong at low levels, will take a bit of uplift.

Divine favour is pretty damn solid as a buff.

Elemental adept allows rerolls I think (been a while), if so then fireball is pretty overpowering.

Magic missiles pick up some significant power.

Stepping into an area of spike growth could shred a powerful enemy.

[LeonBH]

Something would also need to be worked out for Invokers, who can automatically maximize their dice result at level 14 through the Overchannel feature.

[the_brazenburn]

What is the "exploding" benefit only functioned on certain damage dies, and on weapons only? Like, if you roll a 10 on a pike, you get to deal 20 damage, but an 8 on a longsword or a 10 on a fire bolt is still an 8. This would definitely give a boost to martials, and specifically GWM martials, which are supposed to be weaker than casters anyway.

[MrStabby]

I think I might use exploding dice alongside a wild magic zone for a dungeon. Add a little fun and some risk.

[strangebloke]

Elemental adept allows rerolls I think (been a while), if so then fireball is pretty overpowering.

It doesn't. It changes 1's to 2's.

As to the rest of your post, a 1d4 actually doesn't end up being that much better than 1d6. 2.5->3.3 and 3.5->4.2 or something reasonably close to that. The higher dice, like 1d12, lose out a lot but 1d4->1d6 is a gap that doesn't really change in size.

What is the "exploding" benefit only functioned on certain damage dies, and on weapons only? Like, if you roll a 10 on a pike, you get to deal 20 damage, but an 8 on a longsword or a 10 on a fire bolt is still an 8. This would definitely give a boost to martials, and specifically GWM martials, which are supposed to be weaker than casters anyway.
I have suggested allowing 1 iteration of exploding dice as a replacement for GWF. Gives a nice 'micro-crit' feel.

[strangebloke]

Elemental adept allows rerolls I think (been a while), if so then fireball is pretty overpowering.

It doesn't. It changes 1's to 2's.

As to the rest of your post, a 1d4 actually doesn't end up being that much better than 1d6. 2.5->3.3 and 3.5->4.2 or something reasonably close to that. The higher dice, like 1d12, lose out a lot but 1d4->1d6 is a gap that doesn't really change in size.

What is the "exploding" benefit only functioned on certain damage dies, and on weapons only? Like, if you roll a 10 on a pike, you get to deal 20 damage, but an 8 on a longsword or a 10 on a fire bolt is still an 8. This would definitely give a boost to martials, and specifically GWM martials, which are supposed to be weaker than casters anyway.
I have suggested allowing 1 iteration of exploding dice as a replacement for GWF. Gives a nice 'micro-crit' feel.


As an aside, if you want 'every dagger thrust can be lethal' you can always just give PCs less HP per level. After 5th, say, you get HP rounded down for each level. Sucks for casters a little bit, but it's manageable.

Or just overtune the monsters' offensive CRs.

[N810]

Consider how many D6's the high level rogue eventually has on a sneak attack...
Consider again how many when he crits.

[Naanomi]

Doesn’t wild sorcerer have some version of this for their sub-capstone?

[lperkins2]

Exploding dice increase the expected value of a given roll by a factor of (x+1/x), so an exploding d4 (normally EV 2.5) goes to EV 3.125.

The factor is the same no matter how many dice you roll, so a standard fireball does 8d6 for an EV of 28, but an exploding fireball (heh) does (7/6)*28 = 32.7 on average. Of course, it also has higher variance, and I can't say how much that would change.


This is true if the dice are only allowed a single reroll. If dice reroll multiple times, the average scoots a bit higher, and the variance scoots a lot higher. The formula is sum over n for ((size+1)/2)/sizen.

At one point in time, I'd figured out what the resolves to for a simple formula, but these days I usually just dump that sort of thing into wolfram alpha and ask it for the answer.

d4: 3.333
d6: 4.2
d8: 5.14
d10: 6.111
d12: 7.09
d20: 11.05
d100: 51.0


As for using it in actual play, I have in the past, and it works amazingly well. 5e has a bit of a hp bloat problem, especially around level 5-7 or so, where PC damage output hasn't kept up with monster HP. This leads to multiple turns of slogging against creatures that likewise can't pose a serious threat to the PCs. The biggest thing to keep in mind is that at lower levels it will mostly be a disadvantage for the PCs. At level 2, lots of enemies are going to crumple in a single hit anyway, especially a single hit where you roll max damage. The PCs, meanwhile, get a lot more attacks against them than most enemies do, and at low level can still sometimes be dropped by a single crit; if the dice explode too, you might see someone go from full HP to dead in a single strike. In my group, we consider that a feature, but YMMV.

[Eric Diaz]

I like it, and I don't think it would break anything - other than rolling lots of extra dice.

But you might as well just use this for crits. If will benefit some crit-fishing classes a bit, but, heh, it is not like the Champion will suddenly become overpowered because of that, and the barbarian will be okay too IMO.

[FreddyNoNose]

IIRC, back in the 70s, T&t had a system that if you rolled 4 on a d6, you roll again and add. It would continue until it wasn't a 4.

So 6d6 results in:
3, 4, 4, 4, 5, 6 +
1, 2, 4 +
4 +
1

For a total of 38. I like the add roll being on a 4 rather than a 6.

[Davrix]

Like the idea but lets have a little more control on this

Let this be an effect when you crit. You double your dice anyway so more chance of kaboom.

Maybe give everyone a crit range of 19-20 and the classes that have that 18-20

this way it feels a little more special when it happens and not every roll might be OMG WHY

As for invoker and things like that. Its pretty simple. Either they take the max dice damage or they roll and let fate dictate. I don't see the need to change it, maxing all current die is still powerful as hell.

as for spells that are Save vs

I'd probably rule it as something of removing your ability bonus to the DC Save equation to cause exploding dice on damage.

[Aelyn]

This is true if the dice are only allowed a single reroll. If dice reroll multiple times, the average scoots a bit higher, and the variance scoots a lot higher.
Sorry, you're right, I miswrote it. Fully exploding dice don't increase it by a factor of (x+1)/x but by a factor of x/(x-1) - so d4s get an increase of 33% instead of 25%.

That means the fireball would average 33.6 damage instead of the usual 28.

[Knaight]

Sorry, you're right, I miswrote it. Fully exploding dice don't increase it by a factor of (x+1)/x but by a factor of x/(x-1) - so d4s get an increase of 33% instead of 25%.

That means the fireball would average 33.6 damage instead of the usual 28.

Generally yes, with the caveats that rerolls at 1 and 2 change things. An infinite geometric sum can be used based on the fraction of rolls that explode to figure out average numbers of explosions, multiplied by the maximum roll (which every exploding roll gets). This is then added to the average of the final, non exploding roll.

[MadBear]

Something would also need to be worked out for Invokers, who can automatically maximize their dice result at level 14 through the Overchannel feature.

Nah, just let them do infinite damage. :D

[Gorgo]

One thought here is the rule of thumb that variance is generally a bad thing for the players. It's fun when a player gets a rare roll and clobbers a monster, but the GM has an infinite stack of next monsters. When a monster gets a rare roll and one-shots a player character, it's a lot less fun, particularly if bringing characters back from the dead is hard. (This is some advice I got from Pathfinder GM guides, although there it was in the context of not equipping monsters with weapons that did quad-damage on hits.)

[strangebloke]

One thought here is the rule of thumb that variance is generally a bad thing for the players. It's fun when a player gets a rare roll and clobbers a monster, but the GM has an infinite stack of next monsters. When a monster gets a rare roll and one-shots a player character, it's a lot less fun, particularly if bringing characters back from the dead is hard. (This is some advice I got from Pathfinder GM guides, although there it was in the context of not equipping monsters with weapons that did quad-damage on hits.)

That's the thing, lethality is fun at higher levels, when you have the tools to bring people back.

At low levels? It's... less fun. Nobody wants to lose their cool character right out the gate.

It's one reason I really dislike the HP bloat that goes on in 5e. I'd usually mix in some glass cannons, both to give my players tactical goals and to speed up combat and make it more exciting.

[Kane0]

You know the bit under the death and dying rules damage exceeding full HP is outright death? That might actually be relevant again at mid to high levels.

[Asmotherion]

Whats peoples thoughts on playing a game where all damage dice 'explode'?

As in 'if the result of any damage dice results in the highest value of that dice, it is rolled again and added to the total.'

Meaning a single dagger thrust could kill, and big falls and breath weapons are positively scary.

Any unforseen consequences? It boost GWS a fair bit ((re-rolling 1 and 2 on a d6 is pretty potent when 6's also explode).

Pros: Makes combat a bit more deadly, and unpredictable.

Cons: Makes combat a bit more deadly, and unpredictable.

Personally I feel that the critical possibility is already covering this. Perhaps adding a "critical threat" of 19-20 to some weapons (like daggers for example) would be appropriate.

On breath weapons and spells, it can be handled as specific Legendary Actions/Feats to accomplish what you describe.

Making this the default for combat will bring exactly what you describe; dead NPCs and PCs more often.

[sambojin]

Armies of low CR beasts through Conjure Animals might get a bit better (they're already considered a bit of a problem in low level play anyway), just due to the amount of d4s for damage and lots of dice rolling needed already.

Draft horses, elks, giant badgers, giant centipedes, giant poisonous snakes, panthers, pteradons, riding horses, velociraptors and wolves all use d4s for damage, sometimes multiple. Plus, you'll be getting 8 of them per cast. That's 10/21 cases at that CR level (1/4CR), with exploding d4s.

It's not a huge difference, but it combines both the best dice for exploding along with the bucketfull of dice needed to explode them with, in an already useful spell. Going from 5 average damage to 6.66 average damage per 2d4 hit is a nice increase, especially on stuff like wolves with low +damage after the roll (2d4+2). Or can make some combats significantly better weighted for some animals (2d4+4 drafthorses averaging out at 10.66 per hit instead of 9 factors in very nicely to the "10hp lumps" that monsters of varying CRs sometimes come in). It's not a lot, but every bit helps, and Conjure Animals has enough small dice that it will probably help pretty regularly.

[lperkins2]

Sorry, you're right, I miswrote it. Fully exploding dice don't increase it by a factor of (x+1)/x but by a factor of x/(x-1) - so d4s get an increase of 33% instead of 25%.

That means the fireball would average 33.6 damage instead of the usual 28.

See? I knew there was a simple formula for the average damage. Thanks for saving me the trouble.