GURPS 4E: Jumping on the enemy's head

[fretheo]

Hello everyone,

While I was mastering a game I met a situation: player wanted to attack an enemy from above with jumping on his head from some balcony.

Enemy is huge ( with size k ) and distance between him and balcony is d.

The question is: how should we correctly calculate probability of such "hit" and damage for both of them?

I tried to combine different modifiers from Falling, Collision, Dropping, Throwing sections + character skills such as Jumping and Acrobatics, but all I've got - some strange kind of Mario - result damage for player was significantly lower than for his target. And result probability was inadequate high. In addition player has an attack (section Attack from Above). Even tough enemy gets a lot of damage and simply is being "one-shotted".

Perhaps I missed something or such example is described in other books that I didn't read.


Thanks.

[GWJ]

I'd use Flying Kick technique drom Martial Arts p.83, but with collision dmg from falling, if greater than thrust dmg.

And obviously, I'd ALLOW to broke leg in this way, or something. Normal dmg from collision, for attacker. And of course rules to "Attack from Above".

[Kilmore]

A giant's head probably has a higher DR than the DR2 of a human skull.

[Otaku]

Not that I convinced I'll have a "good" answer for you anyway, but more details might be in order. Given what you described in your first paragraph, I don't know how far "off" (if at all) the result is. Responding to your post after having just commented on a thread mired in a disagreement over terminology and a tendency to read to deeply into analogies, metaphors and pop-culture references, I am almost scared to ask but...

...I am not sure what "strange kind of Mario" means in this context. I most definitely am familiar with what I believe to be a decent assortment of Mario games, and that might be the problem: different games have handled the jumping/stomping mechanics in different ways, plus he faces a wide variety of enemy types where at least some justify different results. >.>

[pfharlock]

Basically use the rules for collisions.

Gravity causes you to accelerate at roughly 11 yards per second per second.

The rule for calculating damage is....

1. both parties inflict damage on the other
2. damage is (hp*velocity(in yards per second))/100

so example, you jump from a 3 story building and happen to fall exactly 11 yards, at that point you'd be falling at 11 yards per second, (there is a lookup table for falls in the basic set so you don't have to perform the calculus by hand).

lets say you have 11hp and he has 22hp.

you will do (11*11)/100 dice of damage to him

he'll do (22*11)/100 dice of damage to you

as far as whether you hit him or not, I would think use something like jump skill and include the distance modifier for the vertical distance between you and the guy you are trying to hit, if you make the roll you hit them, and if you don't you miss and connect with the ground instead.

Not sure if this will work for you or not, or if it's even what you guys were going for, so it might be way off base, but that's how I would model it just based on, "hey I jump off this building onto this other guy".

[aesir23]

If the player is using Acrobatics to reduce his falling damage, that would also reduce the damage to his target, for the same reasons (e.g., he's rolling to distribute the force over a larger area and a longer time, this effect must affect the surface he's landing on in the same way thanks to the 3rd law of motion.)

The only difference between the damage taken by the character and the damage taken by the giant should be related to DR.

[BattlemageBob]

damage is not force, damage is the effect of the application of force.
example: Hand to hand, punching somebody in the face does not cause the same amount of damage to both people.

Damage caused by falling will be determined by the weakest spot where force is exerted in the system. For the person getting attacked from above this will likely be the neck, so I would apply damage there to the person being jumped on.

To determine damage for your situation I would first determine if the attacker was able to hit and how well he hit, most likely using the flying kick skill and modifying by the enemys movement speed and the distance your player is jumping from.

Next determine if the enemy was aware of the attack. In real life a lot of force applied to your neck if unsuspected will easily kill a person. If he is aware he will tense his muscles causing it not to be an auto crit. If unaware, treat it as a critical hit.

If the hit isn't enough to knock out the enemy, then your player takes normal falling damage at that height to the leg. Then roll acrobatics to see what happens when he falls from his target at the height of the target and determine additional damage to the player.

If he was able to knockout or kill the target, then he has a slightly softer landing. I would subtract a percentage of his velocity based on how much damage he did to the enemy due to the enemies bones and muscle giving way to the kick and slowing your down before you hit the 3rd derivative of position. Then figure out damage to him based on the new velocity and an acrobatics fall from the new height.

[NorphTehDwarf]

You're running a GURPS: Mario game, aren't you?

[Gollum]

Here is how I would solve the situation (which may not be the good one; it is just my point of view, as mere GM; so feel free to ignore it).

First, there is the falling damage. The giant doesn't move against the PC's move, so it is not really a collision. Or if it is a collision, it is a collision against a stationary target. GURPS rules say: "If a moving object hits a stationary object that is too big to push aside – like the ground, a mountain, or an iceberg – it inflicts its usual collision damage on that object and on itself" (GURPS Lite, page 31 - I don't have my Basic Set at hand, but I don't think it would change anything).

So this damage can be handled like a simple fall with the PC inflicting (his HP x falling speed)/100 dice of damage to the giant and to himself. As said by Aesir23, if he tries to reduce this damage to himself with acrobatics, he will also reduce it to the giant.

Second, this is still an attack. The PC can try to kick the giant to improve the impact. So, the player makes an attack roll (a kicking one) and if it is a success, adds his kicking damage to the falling one.

To summarize things:

• The PC takes falling damage.
• The giant takes falling damage + kicking damage if an attack roll is succesful.

Of course, the giant's skull DR has to be removed of this damage...

[Gollum]

Originally Posted by BattlemageBob

If he was able to knockout or kill the target, then he has a slightly softer landing.

This idea sounds to be a very good one!

If the giant is knocked out or killed by the blow, he falls down which softens the fall. You can consider that the PC takes damage as for a soft ground (HP x falling speed)/100 dice of damage. But if the giant is not knocked out or killed, he keeps standing and the PC takes damage as for a hard ground (HP x falling speed x2)/100 dice of damage; a skull is something very hard.