Post/Author/DateTime	Post
LordSin 03-07-05, 09:20 PM	Ok, +500 xp for the first person to figure this out: A 2,500 lb White Dragon (size L Young Adult) flying at 60 mph (hustle at flight of 200) slams into a 175 lb human. What is the total mass of the dragon upon impact, and what will be the effect of the mass upon a normal human body? I have a player that thinks his +1 large steel shield would have protected him. :rolleyes: edit - how much damage would this have caused the human and how much would have been done to the dragon?
twad 03-07-05, 09:29 PM	well.. im not biologist (orwhatever) but.. its pretty much like being hit by a speeding car. Whole immobile human hit by THAT turns into .... a very dead (or very near death) one. The human body would be crushed by the force of impact, most of the bones (ribs mostly i think) would be totally broken and most internal organs would take some SERIOUS damage... and this is not counting the fact that an impact this strong could result in severe brain damage (if not total destruction of said human skull's..) i may be wrong.. but a steel shield cannot protect you against a car. Have a nice bloody messy day.
feartheinvinceblehamster 03-07-05, 09:30 PM	i'm not even bothering with the math, the dragon takes about 3d6 damage and the human, had better roll well on save vs. mass damage EDIT: twad, lol, we posted at the same time
11d7 03-07-05, 09:41 PM	Ok, +500 xp for the first person to figure this out: A 2,500 lb White Dragon (size L Young Adult) flying at 60 mph (hustle at flight of 200) slams into a 175 lb human. What is the total mass of the dragon upon impact, and what will be the effect of the mass upon a normal human body? I have a player that thinks his +1 large steel shield would have protected him. :rolleyes: edit - how much damage would this have caused the human and how much would have been done to the dragon? 1d6 dmg per 25 lbs so 100d6.
Vatras 03-07-05, 09:57 PM	Well, the dragon deals and receives 20d6 if he falls upon the victim (falling rules), unless he was hurled by the dread hulking hurler (see CW), and if he wants to land upon the human to crush him he is too small by standard rule (MM). If he does a charge attack he deals damage with his bite as per the rules, if he hits. Morale: forget about physics in D&D, because it does not matter whats the mass of the dragon (which is not altered by speed, btw), he can only deal the listed damage. "The dragon flies at you with 20 miles per hour and crushes you and your puny shield..." is good for storytelling systems, but has little to do with D&D combat rules.
The Jade Samurai 03-07-05, 10:34 PM	I have to agree with Vatras or Dragons would need a major adjustment on thier CR
Bregalad 03-07-05, 10:43 PM	Momentum = Mass x velocity. Pounds are force, not mass, but since gravity is the same pounds are good enough. Using Newton's law of conservation of momentum, and assuming a closed system, actual equation would be: Mass of dragon = 2500 Mass of man = 175 (2500 (dragon) x 60 (dragon velocity in mph)) + 0 (man standing still has zero momentum) = (2500 x speed of dragon after impact) + (175 x speed of man flying thru the air) 100d6 of damage is a high estimate, unless the dragon has zero speed after the hit, although I like the reasoning. So lets assume that the dragon loses speed proportional to the weight difference: 175/2500 = .07 .07x60 = 4.2 mph lost from dragon speed Dragon's post impact speed = 55.8 2500x60 = 2500x55.8 + 175xman's speed Mans speed flying through the air is 60 mph (nice eh? I set it up like that hehe) which is about the speed after falling 30' (rounded up) So best for him is that he takes 3d6 damage or so. Problem is that this does not work, cause the body/armor/etc will change shape on impact throwing the whole thing off as well as absorbing energy in the form of internal damage, broken bones, etc. Works nice for iron bricks in a vacuum however. My thought is the max damage from falling is 20d6 (highest impact damage), so do that and throw him back about 30'. "Look ma, Ill stop the train with my garbage can lid!" If he argues the shield, keep in mind thats enough force to knock the shield into him at GREAT force, and the shield actually does the damage (maybe its a +1 "Spring shield of great impact absorption"?). Its kinda like arguing that holding onto the steering wheel and locking your arms in place really hard will keep you from smashing the windshield in a car crash Do I get any xp now? Oh yeah, see what Vatras said too. NOTE TO THOSE WHO KNOW PHYSICS - Yes, I know this isnt the Impulse equation. Yes, I know this is an oversimplification. Yes, I know I did that too. Yes, I know I did not do that either.
LordSin 03-07-05, 11:03 PM	Bregalad gets +500 xp! :cool:
gorzan 03-07-05, 11:21 PM	vatras has a big point going for him there. although the dragon -could- do that, it would be completely out of any and all rules, and the CR for all dragons (or indeed anything weight-y that has a high speed) would have to be increased by lots. Why bother using a bite attack that deals 2d6+14 when you can just bodyslam with a touch attack, dealing 100d6? If you're going for cinematics here, be fair and let the player roll a reflex to avoid being hit or be knocked prone, taking some symbolic amount of non-lethal damage.
artman 03-07-05, 11:34 PM	Conversions: Dragon weighs 2,500 [lbs] -> mass = 255 [kg] Speed = 60 [miles/h] -> 27.55 [m/s] KE=(1/2)mv^2 KE=(1/2)(255 [kg])(27.55 [m/s])^2 = 96773 [Joules] For comparison, in the US motorcylce helmets are designed to take around 120 Joules of impact energy.
LordSin 03-07-05, 11:53 PM	Conversions: Dragon weighs 2,500 [lbs] -> mass = 255 [kg] Speed = 60 [miles/h] -> 27.55 [m/s] KE=(1/2)mv^2 KE=(1/2)(255 [kg])(27.55 [m/s])^2 = 96773 [Joules] For comparison, in the US motorcylce helmets are designed to take around 120 Joules of impact energy. Ooooo..... You get 500 xp too! :D :D :D
artman 03-07-05, 11:53 PM	For completeness... Using the potential energy equation: 96773 [Joules] = mgy y=38.7 [m] -> 127 [ft] From DMG 303, for every 200 lbs the object deals 1d6 damage, provided it fell at least 10 ft. The dragon, 2500 lbs, would hit with the same force as if had fallen from 127 ft onto the human. Falling distance will be rounded to 120 ft, since D&D rounds down. As I figure it: 12d6+11d6 = 23d6 This is surviveable. The sheild would not help as it is an area affect. THe PC should get a Ref check for half damage.
SnowbearK 03-07-05, 11:55 PM	Ever drive your car at 70mph into a swarm of bugs? Yeah, like that.
Wizard 03-08-05, 01:52 AM	I gotta warn you, though...if your players are smart, expect to see your druid wildshape to an elephant after wind walking.
SnowbearK 03-08-05, 03:21 AM	Except an elephant is more likely to splatter on impact as well. Ever seen what a real body looks like of a person who's just jumped off an 8 story building and hit the pavement? Or, for a less humanocentric example, watch Tremors. A falling dragon would splatter as well, btw. A dragon who's "charging" through the air is able to make the adjustments necessary, brace where needed, and bend where needed to minimize the damage to itself. A "controlled" fall, essentially.
LordSin 03-08-05, 04:54 AM	The dragon in question wasn't falling, it was doing a "strafing run" directly at the group of characters. The group scattered, and one of them blinded the dragon with a spell. The dragon was flying low, paralel to the ground, didn't see what was in front of him, and slammed into the character (who had chosen to run in the same direction the dragon was flying). A reflex save (DC 20 because of the speed) was failed, so the character took full damage, killing him (yes, the dragon took damage too). The protest went roughly: "Ok, well you failed you save, so you're going to take full damage, which is... (I forget the actual number, but it was upwards of 90 or so on 20d6) damage. Make a save to avoid death from Massive Damage." "But I've got a shield! That should have saved me!" "How in the world would your shield save you? You were just hit by a bus traveling at highway speed. A shield is not going to save you." "But I've got a +1 shield!" (5 minutes of laughter follows) :evillaugh "Did you make your save versus Massive Damage?" "No..." "Well, you're dead then." "But I've got a +1 shield!" (15 minutes of laughter follows) :rofl:
Drachasor 03-08-05, 09:08 AM	For completeness... Using the potential energy equation: 96773 [Joules] = mgy y=38.7 [m] -> 127 [ft] From DMG 303, for every 200 lbs the object deals 1d6 damage, provided it fell at least 10 ft. The dragon, 2500 lbs, would hit with the same force as if had fallen from 127 ft onto the human. Falling distance will be rounded to 120 ft, since D&D rounds down. As I figure it: 12d6+11d6 = 23d6 This is surviveable. The sheild would not help as it is an area affect. THe PC should get a Ref check for half damage. Well, as it has been said, the Dragon would take falling damage, though the rules above have their flaws. Additionally, the human is so small compared to the Dragon, that it is unreasonable to suppose he is between the Dragon and the ground at all times. The Dragon is just going to hit a lot more ground than human. If the object isn't going to land solidly on the human (and in this case it is basically impossible for such a solid landing), then you can't assume the 1d6/200lb rule applies. 2500x60 = 2500x55.8 + 175xman's speed Mans speed flying through the air is 60 mph (nice eh? I set it up like that hehe) which is about the speed after falling 30' (rounded up) So best for him is that he takes 3d6 damage or so. Problem is that this does not work, cause the body/armor/etc will change shape on impact throwing the whole thing off as well as absorbing energy in the form of internal damage, broken bones, etc. Works nice for iron bricks in a vacuum however. If anything, 3d6 is high if the Dragon is merely ramming into the human. The Dragon is a lot softer than the ground because it is more elastic. Hence 3d6 for a solid ground isn't going to duplicate the hit well. If the Dragon is going to try to make some sort of attack, it is ill-equipped (lacking a lance or anything like that) unless it does a standard charge attack, which would probably do more damage anyhow. The Dragon would still suffer some damage itself. The Dragon is simply better off attacking normally. -Drachasor
artman 03-08-05, 11:41 AM	Well, as it has been said, the Dragon would take falling damage, though the rules above have their flaws. Additionally, the human is so small compared to the Dragon, that it is unreasonable to suppose he is between the Dragon and the ground at all times. The Dragon is just going to hit a lot more ground than human. If the object isn't going to land solidly on the human (and in this case it is basically impossible for such a solid landing), then you can't assume the 1d6/200lb rule applies. I don't see why the dragon takes falling damage. It sounds like the dragon is not falling. Hitting the human will not cause falling damage to the dragon. There should be some damage to the dragon but not too much. My last post just gives a fast and dirty calculation based on the energy of the dragon. I am not saying that the dragon is falling. It is just that the falling damage rules are the closest situation to the impact of a dragon and physics has a way to translate horizontal energy, KE, into falling energy, PE. My figure of 23d6 of damage is based on that valid transformation. The DMG does not specify size for falling damage. Just weight and height. If you want to take size into account just look and see howmany squares the dragon occupies, divide it's weight by that number. THat should take care of the size problems, as it would give the weight the dragon exerts on one 5x5 square, the spaceof the human. The problem with my equations is that they assume all of the kinetic energy is transfered. It would be valid for a fall or if the human were crushed into a wall. If there was nothing to stop the motion after impact, I would lessen the damage and have the human move with the dragon for a little while. Area affect is still the way to go. Falling damage is still the best analogy for the damage.
Drachasor 03-08-05, 12:19 PM	The problem with my equations is that they assume all of the kinetic energy is transfered. It would be valid for a fall or if the human were crushed into a wall. If there was nothing to stop the motion after impact, I would lessen the damage and have the human move with the dragon for a little while. The Dragon wouldn't turn out too well. He isn't as tough as metal, and even a car gets a good banging after going into a human at 60mph. If he rammed himself into a wall or the ground then it would be even worse. Now, a car ramming someone at 20mph leaves a 27% chance of survival. The average human has about 4 hitpoints or so. So 2d6 damage is more than what is inflicted. That means the dragon won't be doing anymore than 6d6. Of course, the Dragon is going to take damage as well. It will be suffering an equal amount of force applied to it, and it will take the same amount of damage (but you subtract its DR). Of course, this is basically the equivalent of Bull Rushing, and provokes an attack of opportunity...of course Bull Rushing doesn't do any damage, so in game terms this attack does no damage. The character is just pushed back as per the Bull Rushing rules. -Drachasor
silvermist 03-08-05, 02:46 PM	Now, a car ramming someone at 20mph leaves a 27% chance of survival. The average human has about 4 hitpoints or so. So 2d6 damage is more than what is inflicted. That means the dragon won't be doing anymore than 6d6. -Drachasor i believe math involving cars and speed is exponential, not just simple multiplication.
Aricandor 03-08-05, 02:56 PM	Indeed, the forces involved in speed is exponential (as is aerial resistance BTW). For every doubling of speed the force (or resistance) is quadrupled.
FloppyLlama 03-08-05, 03:28 PM	I did this once with a blue dragon, flying in with a quickened breath (free action) and making a Power Dive essentially as per the rules for the feat in the draconomicon. Yep.
Karelzarath 03-08-05, 05:16 PM	"But I've got a +1 shield!" Shades of KotDT. ;) Anyway, as a sanity check, I would top out the damage at 20d6. Per the Falling Object rules (as quoted above), even a 20-ton object falling 2 miles still only deals a max of 20d6 damage. A 2500-lb dragon starts at 12d6 (2500/200 = 12.5), so it would have to "fall" at least 80 ft in the round (or move 160 ft horizontally IMO) before striking the human to do that much damage. I'd also say it's fair to have the damage dealt equally to each, though damage reduction would apply as it's non-magical physical damage. In the end, it amounts to either an accident or an "I'm at 3 hp and I'm taking one of you with me" sort of thing. A dragon can likely deal much more than 20d6 damage in the time it takes its opponents to deal a like amount.
Twofingers 03-08-05, 06:34 PM	ok, i have read a lot of these posts and i agree with half of you more then i should and they other half more then you deserve. picture the dragon swoopin in on you , you fail your save ( what ever it was) and you fail your mass damage save, ok, well the mass of the dragon willl knock that man so hard his kids will have headaches, and depending on the armor may or may not absorb the damage, the shield? lol, ok try this grab a wooden board line it with steel, have a 300lb man charge at you, and see if you can stand up, now that you have done that, multiply that force by almost 10 times over, would you be standing and did that shield help you? 20d6 may be max damage by the book, but that is not the difinative answer. think about a fly under a flyswatter, have you ever hit a fly while flying? how far did it fly? just my opinion, proly dont matter much anyways. Twofingers, hafling rogue may your purse be ever full, and my hands ever quick corpses dont need money anyways. :D
Bane 03-08-05, 07:48 PM	Anyway, as a sanity check, I would top out the damage at 20d6. Per the Falling Object rules (as quoted above), even a 20-ton object falling 2 miles still only deals a max of 20d6 damage. A 2500-lb dragon starts at 12d6 (2500/200 = 12.5), so it would have to "fall" at least 80 ft in the round (or move 160 ft horizontally IMO) before striking the human to do that much damage. I'd also say it's fair to have the damage dealt equally to each, though damage reduction would apply as it's non-magical physical damage. I must respectfully disagree to two of these points. First, I would say that distance travelled horizontally is not as important as speed upon impact. My reasoning is that the dragon is not flying 400', stopping until his initiative comes up again, then going another 400'. This dragon is moving at an average speed of 400'/round. If the dragon ended his round 40' away from the fighter, should he have to back up 120' before he can splatter the fighter like a bug on the windshield? Of course not, because the motion is constant, and the round is just a way of breaking it up into manageable sections. The reason greater falling distance increases damage is because that's how the designers applied gravitational acceleration to the force behind a falling object. It's all a matter of speed. Second, I disagree with both the fighter and the dragon taking equal amounts of damage. Here's my example. I can be shot with paintballs a lot without dying, or even going unconscious. I don't think I have well over 50 hitpoints, but even if each paintball did only 1 subdual damage to me, I can take far more paintballs than it should take to cause me to lose consciousness. Obviously, I take 0 damage from paintballs. The paintballs, however, splatter. They have taken damage. As a human, I have no damage reduction, regeneration, or even natural armor. Therefore, I can only surmise that I took no damage because the paintballs are so much smaller than I am. This is an imperfect analogy, as you could point out that the shells for a 12 gauge shotgun are also much smaller than I am, and I won't be volunteering to get shot with them 50 times. Maybe a better analogy would be to simply ask you if a monk takes damage from bruising his knuckles in the process of pounding armored foes into the ground. After all, it's still flesh hitting metal.
ManinDarkness 03-08-05, 08:19 PM	If the dragon smashes on the fighter or the fighter on the dragon, it is bad news to the fighter. :D
Drachasor 03-08-05, 09:34 PM	i believe math involving cars and speed is exponential, not just simple multiplication. That's not how it works in the game though, and that's the basis of these calculations. If you fall 60' you are going much more than twice as fast as if you fall 30', but you only take twice the damage. And remember people, D&D is a heroic game, not one of gritty realism. The characters do amazing things, and survive perils that would fell dozens upon dozens of more realistic men (or women). The system reflects that. Indeed, it is designed around that idea. If you want gritty realism, then you'll have to find it in another game (or houserule this one to an extraordinary degree). -Drachasor
ManinDarkness 03-09-05, 05:30 PM	Second, I disagree with both the fighter and the dragon taking equal amounts of damage.Proportionally, the fighter takes more damage than the dragon.
Drachasor 03-10-05, 08:38 AM	Second, I disagree with both the fighter and the dragon taking equal amounts of damage. Here's my example. I can be shot with paintballs a lot without dying, or even going unconscious. I don't think I have well over 50 hitpoints, but even if each paintball did only 1 subdual damage to me, I can take far more paintballs than it should take to cause me to lose consciousness. Obviously, I take 0 damage from paintballs. The paintballs, however, splatter. They have taken damage. As a human, I have no damage reduction, regeneration, or even natural armor. Therefore, I can only surmise that I took no damage because the paintballs are so much smaller than I am. This is an imperfect analogy, as you could point out that the shells for a 12 gauge shotgun are also much smaller than I am, and I won't be volunteering to get shot with them 50 times. Maybe a better analogy would be to simply ask you if a monk takes damage from bruising his knuckles in the process of pounding armored foes into the ground. After all, it's still flesh hitting metal. The paintballs aren't dealing even 1 point of damage to you. But that's more than enough to kill them. There are other things in D&D that deal no damage. Weapons that are small enough will deal nothing (if you reduce the size down so it deals 1 damage, then the next reduction is 0). A normal sized and normal insect will deal no damage and have no hitpoints. They don't need any though, because D&D isn't about killing individual insects one at a time. Unlike a bullets, paintballs are not that massive and, I believe, shot out at a much slower velocity. This means there is a lot less energy there, that's why they deal no damage and bullets so obviously do. It is very likely you could not easily shoot paintballs out at a speed that would deal damage. The acceleration you'd need in such a gun might well be enough to break the paintball in the muzzle. -Drachasor
kaeso 03-27-05, 02:37 AM	the effect of the dragon hitting the human... SPLAT!!!
Hengwrt Ellesmere 03-27-05, 03:13 AM	In my game the dragon deals the amount listed for his attacks, no more, no less.
Dreaming_in_the_void 03-27-05, 10:48 AM	1. If the Dragon was actually falling, he would do 20d6 to the human AND take the damage himself as he was out of control and falling. 2. If the dragon was "using his weight" to power his claw attack, that is covered by his outrageous strength bonus. He takes no damage however, as he was in control and not falling. This answers the question of "Why wouldn't a dragon always dive bomb a PC?" -- because he'd take the damage too. 3. Falling damage isn't mitigated in the least by a shield. When skydivers jump out of a plane, do they ever take a shield with them to land on?! OF COURSE NOT! They take a parachute, to slow the fall and lessen the momentum. The player should get a reflex save to try and dive out of the way/under cover, but the shield wouldn't help with that either.
DudeMan101 03-27-05, 05:29 PM	I want 500 xp, so I'll answer the question no one else has yet: what is the dragons mass on impact? I'll asume your numbers on weight and speed are infinetly accurate. 60 mph is 26.8224 m/s, and 2,500 lbs is 113.980925 kg, but since in our case g is constant, units of weight can be substituted as units of mass, 2,500 is a nicer number to work with, and DnD uses lbs, we'll use that. It follows from the Lorentz transformation that impact mass=m(rest)/sqrt[1-(v^2/c^2)]. Therefore, just trust me on this, the dragons impact mass is (2500+1x10^-11) lbs. So, all the values for mass you've been using are off by 1x10^-11 lbs.