Combat Mechanics...

[linux]

Before the question, a little background information on the mechanic:
In this mechanic, each weapon has a damage based on the ability of the weapon to penetrate objects (penetration) and the potential force that can be transmitted through the weapon (the hardness or force.)  Each weapon also has a reach for determining the range of the weapon in melee combat.  So, an example weapon could be a sword with a penetration (P) of 6 a force (F) of 5, and a reach (R) of 4.

 The physical strength of the character applies to the force of the weapon, basically adding itself on as a bonus.  When a character makes a normal attack, the entire strength bonus is applied.  When a character moves balance of the entire body with the blow, essentially using your whole body in the attack, the character should receive more of a bonus to damage, i'm thinking something like 1 and 1/2 of the strength bonus.  This would go the same for a jab attack, making it only 1/2 the strength bonus (the fact that jabs are quicker is part of the combat mechanic but may not be relevant to this question.)  More on this in the question.

 Now, every character in the game has a physical reach, relative to the arm, that is equal to 1/2 their physical size.  They additionally have a physical reach, relative to their leg positioning and balance (for example, leaning towards an opponent when thrusting) that is equal to 1/2 their physical size.  Tactical movement is the other factor in determining reach, wherein you can close the distance between you and your opponent by walking/running/jumping.

 An example character (applied only to this combat mechanic):

Joe the Example Guy
Physical size/height:  8
Strength bonus: 4
Physical reach(arm):  4
Physical reach(leg):  4
his weapon being the sword above: (P: 6 / F: 5 / R: 4)


 Joe can take a stab at a haystack with a reach of 12, quite a distance of 1 and 1/2 'Joes' while getting his 4 strength bonus.  Lets say that Joe is going to leap forward a distance of 6 and essentially lunge with a range of 18, he would get a strength bonus of 6 to Force.

 Suppose Joe has the inkling to not only leap forward but dive forward like a torpedo at his enemy, sword first, arms out, not caring about landing.  His physical reach would now be his size/height of 8, plus his arm's physical reach of 4, plus the sword's reach of 4 totaling 16.  This 16 will be added to his tactical movement (we will use the lunge from above) of 6 totaling a whopping 22.

 Question:  How does the entire body being in the air affect kinetic force when determining damage?  Is this something that needs to be determined by the size of the character?  Has anyone ran into this scenario (the torpedo dive) in a campaign setting, and how did you handle it?

 I have been thinking about using Physical reach of the legs, already determining balance, as a means of determining how the damage should be added to.  For example, when lunging with Joe's leg physical reach of 4, he might receive a bonus of 4 to his Strength bonus.

 I am looking for any opinions on this and welcome any question especially if it furthers the topic.


Thanks in advance.

[Bill Cook]

I assume that this is a mechanic for a system that you're designing and not a mod to something that exists. Given that, and considering the many points you describe, I've got to ask: how relevant is this case to your design goals? It feels to me like something that you're pursuing for its own sake, i.e. because you can conceive it, you feel obligated to address it. To put it another way: what is standard fare, and how exceptional are diving sword attacks?

More generally, in the case of a mod, the dive strikes me as color. Your question suggests additional force; that seems as good an instinct as any.

[linux]

The reason I am pursuing this is because I haven't, personally, seen many mechanics that address the differences between a standing attack and a jumping or diving attack.  For that matter, I also want to see a less general description of the forces in a charging attack and how all of this tactical movement applies to the force behind the swing.  I figure that this would occur quite rarely in actual gameplay but it could have an effect on all tactical movement applied in combat, as I believe it has.

 This is, to confirm bcook's thoughts, not a mod but is part of basic combat in my own system.  I want to see much higher detail and focus in the reach of an attack and the balance of a character during the attack, so I have made these mechanics.

 I would still like to hear any responses about how other systems might handle a running/jumping/diving attack compared to a standing attack (and I know that no one just stands perfectly still and swings their arm, they move the body with the blow.)  I'm looking for specific modifications to the attack in specific terms, abstract responses are still welcome.

[Vaxalon]

D20 games grant a +2 to hit for charging attacks with a melee weapon of any kind, and grant double damage to those receiving a charge who have set a spear or spearlike weapon against a charge.

Funny, that doesn't make much sense when you put it together that way...

[Dauntless]

Since you seem to be going for the realistic approach, I'll chime in here with my own 2 cents...

...In this mechanic, each weapon has a damage based on the ability of the weapon to penetrate objects (penetration) and the potential force that can be transmitted through the weapon

Penetration is simply the net force of the object divided by the area of contact.  In this sense, the tip of a spear has a smaller area than an axe, but does a spear have the same amount of force behind it?

 The physical strength of the character applies to the force of the weapon, basically adding itself on as a bonus.  When a character makes a normal attack, the entire strength bonus is applied....

I think it would be better to see this as the character applying a force to the weapon which accelerates the weapon.  The ability of a character to accelerate a weapon is determined partially by the strength of the character, and partially by the shape of the weapon (and or the mode the weapon is used in).  So a weapon has no inherent force, it only has the force (acceleration) given to it by the wielder.  To think of it another way, the kinetic energy = 1/2 mass x velocity^2, wherein acceleration can be thought of as the instantaneous rate of change of velocity with respect to time.  The stronger the character, the more force he can apply to the object, which in turn gives it a higher velocity in a given time frame.  Higher velocity to a weapon means more kinetic energy (due to increased velocity).

 When a character moves balance of the entire body with the blow, essentially using your whole body in the attack, the character should receive more of a bonus to damage, i'm thinking something like 1 and 1/2 of the strength bonus.  This would go the same for a jab attack, making it only 1/2 the strength bonus (the fact that jabs are quicker is part of the combat mechanic but may not be relevant to this question.)  More on this in the question.

Body mechanics are important, but you can just as easily throw your whole weight behind a jab as you can a swing.  In most martial arts (boxing included), you generate the force of a punch beginning with your hips and you rotate your whole trunk including your shoulder region.  Thus, by the time your arm is fully extended, your shoulders are now almost fully lined up with your target (rather than have your shoulders perpendicular to the target).  Boxers also throw in the technique of lunging forward a little to add the weight of the trunk of their body to the blow.  These two keys are a great way to spot someone with no training in martial arts and someone who's trained extensively.

So perhaps you might want to allow poorly skilled combatants the 1/2 of strength limitation, but I'd do away with that for more advanced practitioners.

 Now, every character in the game has a physical reach, relative to the arm, that is equal to 1/2 their physical size.  They additionally have a physical reach, relative to their leg positioning and balance (for example, leaning towards an opponent when thrusting) that is equal to 1/2 their physical size.  Tactical movement is the other factor in determining reach, wherein you can close the distance between you and your opponent by walking/running/jumping.

Reach also plays an important factor in the timing question you had earlier.  The longer the limbs of a character, the greater an arc the limb must travel through.  This then poses the question...does strength mean primarily how much force you can generate, or does it mean how quickly you can accelerate your own limbs?  Bodybuilders tend to have high force generation, but only so-so on the power (power is work/time), while martial artists and gymnasts may not be able to generate as much force, then can generate what they can much more quickly (they may in fact have greater power than the powerlifters and bodybuilders).  How does this relate to reach?

The strength of a character determines how quickly he can move his limb through an arc.  If I have two characters of equal reach, one with a higher Power than the other, (assuming no reflex component here), the character with the higher Power will hit the target first.  Given two characters, one with a smaller reach but the same power, the smaller reach character will extend his limb fully first (this of course is only important if he is able to reach the other character within his reach limit).  

One other gotcha.  The timing question depends on the mode of attack.  If a character swings a weapon, then the time it takes the blow to land and the amount of force in the blow depends on the radius of the arc of the weapon.  Most people are familiar with mass x acceleration as a net force, but when objects are swung in an arc, there's something called the moment of inertia.  It is a measure of the radius of the arc an object is swung through times the  Mass/delta volume (the integral of the change in mass over it's change in volume).  Think of an axe versus a sword.  Given the same weight and length for both, the axe will hit harder at the blade portion than will the sword.  Why?  Because the change in mass with respect to its volume is much higher in the axe than a sword.  But this is a double edged sword (no pun intended)!!  Even though the axe will hit harder, it also means it takes more time to accelerate it...precisely because of the unbalanced mass.  Moreover, any change in direction of the axe will be more difficult with the axe than the sword.  So axes do more damage, but swords are more versatile.

Again, how does this relate to reach?  Because the longer the reach of the character the greater the arc he must swing the weapon through.  On the one hand, this means he can generate more force because of the greater radius arc the weapon travels through.  But it also means he'll be much slower!  Firstly, he'll be slower because the distance the weapon must travel is greater, and secondly, because of the greater radius, it takes more force to accelerate the weapon.  In other words, he has farther to go and he can't accelerate as fast.  By the time the weapon lands though, it'll have quite a bit of energy in it.

So in a nutshell:
Small reach
Pro-Tends to be faster given same power
Con- Tends to be weaker given same power
Long reach
Pro- Can do more damage
Pro- Can keep your enemy at bay
Con- Tends to be slower than smaller reach

 Question:  How does the entire body being in the air affect kinetic force when determining damage?  Is this something that needs to be determined by the size of the character?  Has anyone ran into this scenario (the torpedo dive) in a campaign setting, and how did you handle it?

Flying leaps and dives aren't as powerful as you'd think.  Remember, for every action, there is an equal and opposite reaction.  When you fly and leap at something and crash into it, you crash into it, and it crashes into you.  However, you have nothing to "brace" against this collision while the other object at the very least has a frictional force.  You simply get your whole mass x acceleration, while the other person "hits" you back with the same force + at the very least frictional force.  By keeping your legs "planted" you can transmit some force back to counter this.  When you are airborne you don't have this ability.  

Flying leaps are good if your opponent is already unbalanced and you can knock him down, or if you simply need to gain height (many Korean kicks were actually derived from the necessity to dismount a rider on horse).

 I have been thinking about using Physical reach of the legs, already determining balance, as a means of determining how the damage should be added to.  For example, when lunging with Joe's leg physical reach of 4, he might receive a bonus of 4 to his Strength bonus.

I think the important thing to remember is that reach doesn't generate force, only power does (which is muscular strength which can apply acceleration to a weapon).  But critical to understanding power is that it is the work/time.  Work is pure strength...i.e how much you can lift for example.  But the time component is crucial.  A bodybuilder might lift 400lbs in 4 seconds, but a martial artist who could could generate 200lbs of pressure in 1 second would have more power.

Again, what does this have to do with reach?  The longer the reach, the more time it takes to get there.  The more time it takes to get there, the more time you have to accelerate the object, hence the object does more damage.  Now this is important for a lunge.  Longer limbs DO add to damage when the weapon is swung in an arc, because then you have a longer lever (but a lunge is a thrust).

As you can see, you make things wickedly complex if you want to make it realistic.

[Hereward The Wake]

at the end of the day power is based upon skill. a less skillful person is going to be able to apply less power, regardless of their natural power, to an attack then some one who is skillful. and all the power means nothing unless applied wih good control. Control coming from skill. also with a skillfull person the power, howver small will be applied in the correct place, whereas the the less skilfull person may apply more strength, but to thewromg place causing less result.

someone needs exceptional power/strength etc, for it to make a differance in a combat situation, the skill is the deciding factor at the end of the day. power with out control is worse than no skill.

[Andrew Morris]

Jonathan-

I don't buy your argument about skill over power. Now, don't get me wrong, skill is important, but I don't think it is to the degree which it seems to me you are implying.

For example, you've got to escape from a cell with two doors. Door A is guarded by a 300-pound, seven foot tall guy with no combat training whatsoever. Door B is guarded by a normal-sized soldier who's had extensive combat training, both in the military and out. Oh, but wait...the skilled fighter guarding Door B is sick. He's barely got enough strength left to hold himself up. Seriously, which guard do think you have a better chance of taking out?

It's an extreme example, I know, but it holds true even when it's not extreme, and balances somewhere in the middle.

[Ron Edwards]

Hello,

Andrew and Jonathan, you need to take such discussions to private email or messaging.

Linux has been very clear about his needs:

I would still like to hear any responses about how other systems might handle a running/jumping/diving attack compared to a standing attack (and I know that no one just stands perfectly still and swings their arm, they move the body with the blow.) I'm looking for specific modifications to the attack in specific terms, abstract responses are still welcome.

I'm moderating pretty forcefully in this case because discussions about "power vs. skill" have very high potential to turn into flames.

Best,
Ron

[ErrathofKosh]

Because Joe is using relatively little of his strength to attack (he used it to propel his body through the air...) and a lot of his weight, I would replace the strength bonus with the size of the character.  Thus, joe would receive a +8, instead of the +6.  It's well nigh impossible to design a system that models any of the laws of Newton, but if you keep them in mind as general guidlines that help you formulate rules, your game will be more "realistic."  

Cheers
one of many Jonathan's on the Forge

[GregS]

Some fantastic posts in this thread.  And special kudos to Dauntless, who said just about everything there is to say on the matter (and in a very, very astute manner).

As for addressing the specifics of the question:  In short, I would only add modifiers to jumps/dives IF (note the capitals) the attack is in a position to gain from the additional energy added by gravity building up force behind it.  So, for example, a "death from above", say jumping down from a tree limb on top of someone, could have a bonus if you wanted because you are actually able to generate more force with the assistance of gravity (though I know many a kenjitsu practitioner that would argue you'd also loose a bunch from not being able to properly center and ground your cut).  Simply jumping in place, however, should not.  The why was covered already, so I shant go into it in detail, sufficed to say you do not actually generate more force by leaping into the air...contrary to whatever hollywood might have told you.  So, too, with dives-- they are no more powerful than a pushed lunge or charge.

[Andrew Morris]

Oops. Sorry about that Linux, Ron. I lost track of the focus of the thread myself. Didn't mean to take it off in another direction.