Movement based damage

[DreadDomain]

Hey guys, need your help here. I seem to recall there was somewhere in the BGB rules about converting movement to dice of damage (you know, to simulate a slam). Going through the book, I can't seem to locate such a rule.

Question 1 : How does movement translate into damage for a slam or a passing strike for example?

Page 159 I have found how to do it for the Leap power (strangely, it is based on level of Power instead of leaping distance) but I find no such mention for the Flight power. In a nutshell, every level (+3m with running start, +2m with standing jump or +1m Vertical jump), add to STR+SIZ on the Damage Bonus table (page 29). So generally 16 levels (+48m with running start) gives +1d6.

In the Superworld book the Smash maneuver is better explained and talking the Impact damage table as an example, it would seem that every +30m gives about +1d6 of damage. Because the damage bonus table is slightly different in Superworld (increment every +10 instead of every +16) it is coherent with the suggestion of +1d6 of damage every +48m in the BGB.

Question 2 : How long does a jump take and is it depemdent on total distance jumped (does a 300m jump takes longer than a 3m jump or is it assumed that the jump is 10 time as fast)?

Page 223 under Falling, it says that each 3m fallen incurs 1d6. Quite a difference with the rate found under Leap!

Question 3 : Is there anywhere a rule/chart about how long it takes to fall? Sure I can just calculate it but I would have assumed that such info would have been readily available in the book.

[soltakss]

The time taken to complete a jump depends on many factors: is it a vertically upwards, vertically downwards or horizontal jump, is it from a standing start or a running jump, is it in atmosphere and so on.

How long a fall takes depends on the factors involved. Falling in a vacuum is different to falling in the atmosphere, how you fall also affects the time taken to fall, due to the varying calculation of Terminal Velocity. Someone spreading arms out will fall slower than someone curled up in a ball or with arms to the side.

The Leap and Smash powers cause damage to an opponent, not to the participant, so the damage will be different to the Falling damage.

The best suggestion I would make would be to put the damage for Falling, Leap and Smash in a table, side by side, and compare them.

[DreadDomain]

The time taken to complete a jump depends on many factors: is it a vertically upwards, vertically downwards or horizontal jump, is it from a standing start or a running jump, is it in atmosphere and so on.

How long a fall takes depends on the factors involved. Falling in a vacuum is different to falling in the atmosphere, how you fall also affects the time taken to fall, due to the varying calculation of Terminal Velocity. Someone spreading arms out will fall slower than someone curled up in a ball or with arms to the side.

Yes, I understand that and your answer makes me realize my question wasn't clear. I was asking if BRP had a "gamist" answer about how long does a jump takes (GURPS and HERO have one) as well as a gamist answer about speed of fall for a "standard" (again from a gamist point of view which means a human falling is Earth's atmosphere) fall. Your answers lead me to believe that it was just left unsaid in the BGB which is fine.

The Leap and Smash powers cause damage to an opponent, not to the participant, so the damage will be different to the Falling damage.

The best suggestion I would make would be to put the damage for Falling, Leap and Smash in a table, side by side, and compare them.

Sure, the alternative is to do the work myself. Not a biggie but I was a bit surprised that Smash damage was left out of the BGB.

[Evilschemer]

Hey DreadDomain, I have created spreadsheets for other games (Fuzion, Mutants and Masterminds) to calculate the zenith of a jump and the duration of the leap. A super-leap is essentially the same as firing a ballistic projectile. If you know the total horizontal distance, and the angle of the trajectory (I assume all super-leaps for distance are at 45-degrees), and the gravity (assuming 1), there are formulas for calculating the launch velocity, height at zenith, impact velocity, and duration of leap.

If you know the distance in feet, here's the EXCEL formula to determine launch velocity in feet/second:

=(([DISTANCE IN FEET]*32.17)/SIN(90*PI()/180))^0.5

Using that, you can calculate the height in feet:

=([LAUNCH VELOCITY IN FEET/SECOND]*SIN(45*PI()/180))^2/64.34

Time aloft in seconds:

=([LAUNCH VELOCITY IN FEET/SECOND]*2)/32

From there, it's just a matter of multiplying by seconds-per-round, feet-per-second into miles-per-hour (=([LAUNCH VELOCITY IN FEET/SECOND]*0.1136)), etc.

Ironically given the complicated math above, I'm keeping things simple by ignoring things like wind resistance, aerodynamics, etc.

[DreadDomain]

Thanks for the equations Evilschemer.

Actually my questions were more in the line of "how does BRP do it / does BRP even consider it?" instead of what would be a realistic even if simplified way to find the values. Nonetheless, your equations are helpful.

I see that no one tried to answer the original question :

Question 1 : In BRP, how does movement translate into damage for a slam or a passing strike for example?

[Evilschemer]

Thanks for the equations Evilschemer.

Actually my questions were more in the line of "how does BRP do it / does BRP even consider it?" instead of what would be a realistic even if simplified way to find the values. Nonetheless, your equations are helpful.

I see that no one tried to answer the original question :

Question 1 : In BRP, how does movement translate into damage for a slam or a passing strike for example?

Two places.

BRP page 61, Grapple Effects, Throw Target. If your character wins, the defender is thrown: he or she flies 1D6 meters, is automatically knocked down, and must make an Agility roll or suffer 1D6 point of general damage.

BRP page 223, Falling. A falling character takes 1D6 base damage for every 3 meters fallen. If the character was thrown with conderable velocity, the gamemaster may even double the damage dice for a fall.

This is over-simplistic, of course. But you can translate the above into damage per velocity.

the velocity at a given impact is sqrt(2*9.8*distance in meters)

3 meters = 7.67 m/s = 1d6

6 meters = 10.84 m/s = 2d6

9 meters = 13.28 m/s = 3d6

12 meters = 15.34 m/s = 4d6

15 meters = 17.15 m/s = 5d6

There's no easy formula for determining dice of damage per meters per second velocity. Essentially, use the table above, then add +1d6 for every +1m/s after 17.

[Evilschemer]

Here's a better table that converts meters/sec to km/hour to MOVE (assuming 1 MOVE = 3 meters per 12-second combat round) with damage.

m/sec	km/h	MOV	Damage

8	28	31	1D6

11	39	43	2D6

13	48	53	3D6

15	55	61	4D6

17	62	69	5D6

19	68	75	6D6

20	73	81	7D6

22	78	87	8D6

23	83	92	9D6

24	87	97	10D6

25	92	102	11D6

27	96	106	12D6

28	100	111	13D6

29	103	115	14D6

30	107	119	15D6

31	110	123	16D6

32	114	126	17D6

33	117	130	18D6

33	120	134	19D6

34	123	137	20D6

35	127	141	21D6

36	129	144	22D6

37	132	147	23D6

38	135	150	24D6

38	138	153	25D6

39	141	156	26D6

40	143	159	27D6

41	146	162	28D6

41	149	165	29D6

42	151	168	30D6

43	154	171	31D6

43	156	174	32D6

44	159	176	33D6

[soltakss]

Here's a better table that converts meters/sec to km/hour to MOVE (assuming 1 MOVE = 3 meters per 12-second combat round) with damage.

And that shows up a major problem.

If you assume that Momentum is proportional to damage, then something moving at 10m/s does 2D6 damage, something moving twice as fast (20 m/s) should do twice as much damage but does 7D6 damage and something twice as fast again (40 m/s) does 27D6 damage.

Those figures just don't make sense to me.

[DreadDomain]

I agree with Simon. Progression seems off and damage way too high.

[Evilschemer]

that's because the game ties dice damage to height fallen, not to velocity/momentum. Your velocity increases exponentially with height, but damage is linear with height.

So, either you can assume that the damage progression is not linear, meaning that 4D6 is not twice the actual damage of 2D6 but actually some greater amount, or you can change the falling damage rules.

Of course, this is REALLY because equating falling damage to distance fallen is a lot easier than trying to communicate damage times velocity at time of impact in an RPG.

[DreadDomain]

True enough. Both HERO and GURPS use a table to correlate distance fallen and velocity in order to find out damage.

Both the rules you quote, Falling and Grappling, are not really helpful to translate movement (velocity) into damage. Falling uses distance fallen (which in my opinion doesn't make sense) and grappling does imply velocity damage but velocity is unknown. The only hint that we have in the BGB is the Leap powers who tells us that every level add to STR+SIZ on the Damage Bonus table. Assuming every leap takes the same amount of time irrespective of distance leapt (unrealistic but a simplification that is I believe acceptable) levels equal velocity with the caveat that depending on type of jump (vertical, standing or running) the distance leapt isn't the same.

Based on that every 16m or 32m or 48m (16 levels) roughly gives +1d6 of damage.

Now depending on how long does it time to make a jump (BRP says between a few seconds and a combat round), velocity could be calculated and a table for falling damage could be made.

[soltakss]

that's because the game ties dice damage to height fallen, not to velocity/momentum. Your velocity increases exponentially with height, but damage is linear with height.

So, either you can assume that the damage progression is not linear, meaning that 4D6 is not twice the actual damage of 2D6 but actually some greater amount, or you can change the falling damage rules.

Of course, this is REALLY because equating falling damage to distance fallen is a lot easier than trying to communicate damage times velocity at time of impact in an RPG.

Ah, I hadn't realised that this is the Falling Damage Table rather than a Velocity Damage Table. That makes sense as velocuty does increase with height fallen, so damage should also increase.

According to Wikipedia, as good a source as any, the Terminal Velocity of a skydiver is 54m/s, which we hit when we fall 150m, or thereabouts, doing 51D6 damage.

It might be better using the ballistics equations and seeing how they turn out.