Scaling falling damage to size?

[Mok]

Whether it is 3.5, Pathfinder or 4E all of these systems have fixed damage dice for falling, 1d6 per 10 feet for 3.5/PF or 1d10 per 10 feet for 4E.

It's fine and simple. It assumes that PCs are medium or small creatures and so their mass is close enough that when they fall they take an amount of damage that is fairly comparable. The rules are really intended to see what happens to PCs most of the time, rather than seeing what happens when bigger or small creatures fall.

However, when it comes to weapons then the "physics engine" kicks in a bit more (Force x Mass = Momentum) and suddenly the mass of the weapon becomes important, and so we have die steps keyed to the size of the creature. It's a bit more fussy and detailed, but since the main point of D&D is to conduct combat then this level of granularity is generally desired.

Now if you wanted to extend the physics engine a bit more and didn't mind that extra little bit of information to keep track of it seems rather simple and realistic to key falling damage to die steps based on size. Something like:

3.5/PF

Fine 1
Diminutive 1d2
Tiny 1d3
Small 1d4
Medium 1d6
Large 1d8
Huge 1d10
Gargantuan 1d12
Colossal 2d6

4E

Fine 1d2 (I think they got rid of this size?)
Diminutive 1d3
Tiny 1d4
Small 1d6
Medium 1d10
Large 1d12
Huge 2d6
Gargantuan 2d8
Colossal 3d6

Does this sound right? Or at least not game breaking?

[Mistwalker]

I think that it is a detail that is not really needed, that it will add in a complexity (needing to look up a table) that will not add to the game play experience.

There is also arguments to be made for larger creatures being tougher (having to have tougher bones and such to carry around that extra weight).

As well, arguments for having to revisit the 10' criteria, because proportionally, a 20' creature should not be penalized the same as a 5' or 6' creature for falling the same distance. That is, if the fall was 20', should the 20' creature take the same penalty for falling it's height as would a 5'-6' creature falling 3 to 4 times it's height?

Then there is terminal velocity, which is the same for a ton of bricks as it is for a ton of feathers.

A 1d6 per 10' of falling rule is simple, easy to apply and easy to remember.

[Kolokotroni]

Mistwalker wrote:

I think that it is a detail that is not really needed, that it will add in a complexity (needing to look up a table) that will not add to the game play experience.

There is also arguments to be made for larger creatures being tougher (having to have tougher bones and such to carry around that extra weight).

As well, arguments for having to revisit the 10' criteria, because proportionally, a 20' creature should not be penalized the same as a 5' or 6' creature for falling the same distance. That is, if the fall was 20', should the 20' creature take the same penalty for falling it's height as would a 5'-6' creature falling 3 to 4 times it's height?

Then there is terminal velocity, which is the same for a ton of bricks as it is for a ton of feathers.

A 1d6 per 10' of falling rule is simple, easy to apply and easy to remember.

I agree, I think that it adds alot of complexity without truly representing the 'reality' of the situation. I think it would make certain affects dramitically more or less powerful against big or small creatures. There are ways to make things take falling damage (usually involving magic, or cliffs) that would change very significantly in how they play out depending on size. And given that large and small creatures will fall at roughly the same speed (depending on wind resistance), though you have a greater mass on the larger creatures, you also have a potentially larger surface area to distribute the force of the fall, which would reduce the impact. It's why 'pro' wrestlers try to land flat on their backs with the arms outstretched when they get thrown around. So the collosal creature may hit with more force then the small one overall, but the force on any part of its body (and thus the impact) will be distributed over its larger surface and thus be less or equal to the smaller creature which has less surface to distribute the force.

[dulsin]

If you would like to add a modification to falling damage it should be to ramp up the damage faster. A person is much more likely to survive a 10' fall 10 times than a 100' fall once.

One of the old optional rules was a geometric ramping of falling damage.

10' - 1d6
20' - 3d6
30' - 6d6
40' - 10d6
50' - 15d6
60' - 21d6
70' - 28d6
80' - 36d6
90' - 45d6
100' - 55d6

Using this scale any fall over 100' would be almost universally fatal. Fear of falling is one of the naturally ingrained phobias and should be part of any game that wants to challenge players.

This scale also makes the monks slow fall ability more powerful. Even a 10' reduction would significantly reduce falling damage on a scale like this.

[Mok]

dulsin wrote:

If you would like to add a modification to falling damage it should be to ramp up the damage faster. A person is much more likely to survive a 10' fall 10 times than a 100' fall once.

That's an interesting approach, although how would the extreme sizes get affected?

I don't really have the physics in me, but intuitively I'm thinking that an ant falling from a 100' drop isn't going to be damaged by the fall, while an elephant falling from just a short distance is going to have broken legs, ribs, etc.

[Kolokotroni]

Mok wrote:

dulsin wrote:

If you would like to add a modification to falling damage it should be to ramp up the damage faster. A person is much more likely to survive a 10' fall 10 times than a 100' fall once.

That's an interesting approach, although how would the extreme sizes get affected?

I don't really have the physics in me, but intuitively I'm thinking that an ant falling from a 100' drop isn't going to be damaged by the fall, while an elephant falling from just a short distance is going to have broken legs, ribs, etc.

It depends on the animal, which is the inherant problem. Drop a cat out of a window, and because of the way its knees bend, its likely to be uninjured. A dog of the same size on the other hand will almost certianly be injured.

[dulsin]

The reason that small creatures can handle falls better than larger ones is a question of the area versus the size.

The basic area of a creature will change by the square of his size but his mass is changing by a cube factor.

Take a three balls of the same density and calculate the surface area and mass 3' 6' 12'

3' -- 108'sq - 25lbs
6' -- 432'sq - 200lbs
12' - 1728'sq - 1600lbs

The smaller objects have a higher air resistance based on surface area / mass.

3' - 108/25 = 4.32
6' - 432/200 = 2.16
12' - 1728/1600 = 1.08

The larger the effective drag the lower the terminal velocity and the longer it takes get to terminal velocity.

At some point a very small creature has so much drag they will never take damage.

[Dennis da Ogre]

Mok wrote:

Fine 1

Diminutive 1d2
Tiny 1d3
Small 1d4
Medium 1d6
Large 1d8
Huge 1d10
Gargantuan 1d12
Colossal 2d6

I came up with more or less the same idea some time ago. I just used the weapon size chart. Weapon 'size' is the person falling.

While the type of creature falling (dog versus cat) will have some effect but that can be modeled by an acrobatics check. More significantly larger creatures of the same type are more likely to take greater damage than a small creature of the same type. If a terrier fell 20' it would likely be fine, a great dane falling the same distance is going to break a leg at the very least and has a significant chance of death.

So yeah, I think it's a great optional/ home rule though I wouldn't put it in the core book.

[TriOmegaZero]

I plan on using a different rule if I ever have a character take a fall. Keep the d6 per 10ft, but the total rolled is the percentage of total hit points lost. So if you roll 45 on the dice, you lose 45% of your total hit points. Not your hit point total. So if you were at 40% health, you better hope someone can heal you. Mostly I thought of this to prevent high level characters from thinking they can jump off cliffs and survive all the time.

[Weylin]

Another factor in falling damage is the abstract nature of hit points themselves.

While yes a 40 foot fall should kill most people outright, hit points are not raw damage capacity. Taking 4d6 pretty much means your average 1st to 2nd NPC Class is dead. BUt through luck, divine favor, destinty, skill, etc a 6th level fighter will probably survive the drop.

If you want more realistic and fatal damage from falls, apply the damage directly as Constitution Drain (on average a 30 foot drop would kill your average 10 Con person).

As for size, larger creatures are in general going to be much tougher. the density of a Storm Giant's bones must be unbelievable to support such a massive bipedal creature. Even a 40 foot drop is not going to do much to him probably...not to mention that is roughly like a human falling 12 feet.

-Weylin