Calculating damage taken from something falling on somebody

[Ekzanimus]

D&D 5ed have quick rules for calculating damage taken from falling but are there any rules for damage taken from something falling on you? For example how much damage will take your average goblin if there is a very angry Enlarged duergar whose weight was doubled by graviturgist falling from, say, 20 feet on him?

[Segev]

The easiest way to calculate it would just be to say the damage is mutual, but I do get why that's unsatisfying; the small pebble falling 20 feet onto your helmet should do less damage than the enlarged dueargar falling 20 feet onto your everything.

For a really quick-and-dirty thing to give it some flavor (no promises as to balance or efficacy), how about adding the difference between the size of the faller and the size of the fallee in d6s? Basically, the person being fallen upon takes +1d6 for each size category larger the being falling on him is, and -1d6 (minimum 0) for each size category smaller than him the falling being is.

So if an enlarged duergar (size Large) falls 30 feet onto a goblin (size Small), the dueargar takes normal falling damage (3d6), and the goblin takes the same damage, plus two more d6 due to the much larger creature falling on him. So the goblin takes 5d6 bludgeoning damage from the falling enlarged duergar.

I repeat: this is not anywhere in the rules (that I know of); I am just making something up that I feel is usable to simulate enough of what you're going for.

You might also make the goblin make a Strength save or be knocked prone. Or maybe treat it like the duergar is making a Shove attack, only the duergar can choose to add or subtract his normal bonus from it rather than having to add it. You know, if the duergar didn't WANT to knock the goblin prone, for some reason.

[LudicSavant]

D&D 5ed have quick rules for calculating damage taken from falling but are there any rules for damage taken from something falling on you? For example how much damage will take your average goblin if there is a very angry Enlarged duergar whose weight was doubled by graviturgist falling from, say, 20 feet on him?

Check the "improvising damage" section in the DMG. Several of its examples include stuff falling on people (including an entire flying fortress) so you can kinda extrapolate from there.

One thing we can tell from this is that it isn't linear. Something twice as heavy doesn't do twice as much damage. Instead it looks like you need exponentially more mass for each extra die of damage.

Remember, a giant throwing a giant boulder with superhuman strength only does a few dice of damage, so dropping an Enlarged Duergar probably shouldn't do that much damage.

[Ekzanimus]

Thank you very much! I didn't know about examples from the "Improvising damage" table and I really like the idea of adding 1d6 for every size category. I can work with that.

[Galithar]

Thank you very much! I didn't know about examples from the "Improvising damage" table and I really like the idea of adding 1d6 for every size category. I can work with that.

I also like the possibility of changing the die size.
So in the example if enlarged Duergar and goblin the fall damage would be 3d6 to the Duergar and 3d10 for the Goblin. At that height the difference in damage between the two methods is minimal (5d6 avg 17.5 // 3d10 avg is 16.5) but changing the die size makes the distance fallen more important. A long fall 100 feet for example would see the damage difference being 12d6 (avg 42) versus 10d10 (avg 55). Also it avoids the falling damage caps at 20d6 making a fall fr 200 feet deal the same 20d6 to both sides. (Though you could obviously just ignore that and make it deal 22d6 to the goblin anyways)

[TigerT20]

I also like the possibility of changing the die size.
So in the example if enlarged Duergar and goblin the fall damage would be 3d6 to the Duergar and 3d10 for the Goblin. At that height the difference in damage between the two methods is minimal (5d6 avg 17.5 // 3d10 avg is 16.5) but changing the die size makes the distance fallen more important. A long fall 100 feet for example would see the damage difference being 12d6 (avg 42) versus 10d10 (avg 55). Also it avoids the falling damage caps at 20d6 making a fall fr 200 feet deal the same 20d6 to both sides. (Though you could obviously just ignore that and make it deal 22d6 to the goblin anyways)

I've always had the idea of changing the dice size for falling damage because let's be honest if an elephant and a chicken both fall the same distance, the elephant will be worse off.

Something like d4 for Tiny, d6 for Small/Medium, d8 for large, etc

[Galithar]

I've always had the idea of changing the dice size for falling damage because let's be honest if an elephant and a chicken both fall the same distance, the elephant will be worse off.

Something like d4 for Tiny, d6 for Small/Medium, d8 for large, etc

That's true. I believe the terminal velocity of an ant is such that it can fall any distance and survive it's impact virtually unscathed.