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Old 01-12-2012, 05:54 PM   #1
vitruvian
 
Join Date: Aug 2004
Default Have I Got Jumping Velocity Right?

I had thought that your velocity while jumping any distance, even (or especially) when extended for Super Jump, was equal to your Basic Move (or ground move, if you accelerated to a higher speed using Enhanced Move before jumping), or 1/5 your jumping distance, whichever was greater.

Is that correct, or are all jumps now assumed to take one turn, with velocity equal to distance? I only ask because in the first Dungeon Fantasy Adventure, there's a creature with a Move 3 and jumping distance of of 8 or 16 yards, and its slam damage seems to be calculated using 8 or 16 as its velocity...
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Old 01-12-2012, 10:24 PM   #2
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Default Re: Have I Got Jumping Velocity Right?

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Originally Posted by vitruvian View Post
I only ask because in the first Dungeon Fantasy Adventure, there's a creature with a Move 3 and jumping distance of of 8 or 16 yards, and its slam damage seems to be calculated using 8 or 16 as its velocity...
I would conclude that the creature's slam attacks are the result of its jumping into you.

In general, I would say your average velocity for a turn (in yards per second) would be how many yards you moved that turn, whether it be due to running or jumping. This is not necessarily the same as your instantaneous velocity at the end of your turn.
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Old 01-12-2012, 10:27 PM   #3
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Default Re: Have I Got Jumping Velocity Right?

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I would conclude that the creature's slam attacks are the result of its jumping into you.

In general, I would say your average velocity for a turn (in yards per second) would be how many yards you moved that turn, whether it be due to running or jumping. This is not necessarily the same as your instantaneous velocity at the end of your turn.
That doesn't answer the question, though. If I'm correct, a Move 3 creature jumping 8 yards will take 3 turns for the jump, and have a Move 3 in any of those turns. You seem to be assuming that any jump is completed in one turn, which is counter to the RAW as far as I can tell.
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Old 01-12-2012, 11:08 PM   #4
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Default Re: Have I Got Jumping Velocity Right?

Those turtles are pretty weird in general but their slam damage is clearly worked out incorrectly. Powers is very clear about Super Jump resulting in multiple seconds airborne.

Presumably they were play tested with those slam stats and worked so you could just give them vastly higher levels of Super Jump and things would be fine (also hilarious).
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Old 01-12-2012, 11:24 PM   #5
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Default Re: Have I Got Jumping Velocity Right?

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Originally Posted by vitruvian View Post
That doesn't answer the question, though. If I'm correct, a Move 3 creature jumping 8 yards will take 3 turns for the jump, and have a Move 3 in any of those turns. You seem to be assuming that any jump is completed in one turn, which is counter to the RAW as far as I can tell.
I don't have the rules for the creature in question, but I think I see what's going on.

When a person jumps, some of their forward velocity is based on their velocity before they jumped and some will be based on their pushing off when the jump. E.g. For a standing broad jump, your move before the jump is 0, yet you jump 2 yards; the jump does not take an infinite amount of time.

My guess is that these (turtle?) creatures are slow. Their jumping distance is not based off their speed prior to the jump, but their push-off ability when they decide to jump. My guess is you're supposed to allow them to broad jump the 8 yards if they want to. This jump would take only one turn and could end in a slam.
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Old 01-13-2012, 12:02 AM   #6
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Default Re: Have I Got Jumping Velocity Right?

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Originally Posted by vitruvian View Post
... If I'm correct, a Move 3 creature jumping 8 yards will take 3 turns for the jump, and have a Move 3 in any of those turns...
That matches my understanding. The description of Super Jump is very clear that your "... Move while jumping is the greater of your normal ground Move and 1/5 your maximum long jump distance (thus, your maximum jump never takes more than five seconds) ..." (p. B89). The Greater Bounding Turtle has ground Move 3 and a maximum jumping distance of 16 yards, which makes its jumping Move 3.2 yards (it doesn't mention rounding), so it will take 2.5 seconds to make an 8-yard jump.

I can't figure out how the slam damage is calculated at all. If 4d+4 equals 5.2 dice, then the slam damage formula (with HP = 45) implies a velocity of 11.5?
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Old 01-13-2012, 01:44 AM   #7
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Default Re: Have I Got Jumping Velocity Right?

The turtles are figured out right, at least for damage. But not flight time I think.
A combat jump for the Great Bounding turtle is Move 3 super Jump 4 for 16y
Thats move 3*2-3=3 base *16 for 16y standing start. Half that (Basic p352) for a combat jump
So they jump 8y in combat and 16y out of combat which matches the stat block.
Super jump velocity would be max of 3 from Move or max long jump.
Damage as noted in Super Jump is based on your max jump not velocity, probably because of the push off effect described above. After all your more like a canon then a running train. So damage is 8*45/100=3.6 rounded up since more then .5 to 4d and +1 per die for AoA (Strong) so 4d+4 for combat slam.
math works out for the longer jump too.
Only catch is I think they take a couple of turns to land unless within 3y.
Oh and the DR 12 means they take an average of 6 HP a hit also, so not a real good strategy. Unless the falling defense applies which would be no damage up to 3y (10.66 feet)
I want to know if that's the case though.
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Old 01-13-2012, 02:03 AM   #8
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Default Re: Have I Got Jumping Velocity Right?

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... Damage as noted in Super Jump is based on your max jump not velocity...
Your Super Jump slam damage is not based on your maximum jumping distance, it's based on "your maximum jumping Move" (p. B89) ... which in this case is 3.2 yards.

45*3.2/100 = 1.44 or about 1d+1 (1d+2 with AoA Strong).
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Old 01-13-2012, 02:36 AM   #9
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Default Re: Have I Got Jumping Velocity Right?

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Your Super Jump slam damage is not based on your maximum jumping distance, it's based on "your maximum jumping Move" (p. B89) ... which in this case is 3.2 yards.

45*3.2/100 = 1.44 or about 1d+1 (1d+2 with AoA Strong).
Dang it and Move is capitalized to so clearly referring to the attribute.
I just read that too. We need Kromm to chime in here.
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Old 01-13-2012, 08:03 AM   #10
vitruvian
 
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Default Re: Have I Got Jumping Velocity Right?

And the thing is, I like the turtles and it seems like if they're leaping that far they should hit pretty hard. This is a case where the 'breaking' of the rule seems intuitively better and more accurate than the rule in RAW, if only because what I remember of physics suggests you're not going to go 16 yards if your takeoff velocity is only 3 yards per second, or even ~1.4 x 3 = ~4.2 yards per second at a 45 degree angle.

Yeah, physics agrees with me... went to http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html

A takeoff velocity of 4 m/s at a 45 degree angle would only carry the turtle about 1.6 meters (~5 feet) horizontally. Conversely, a range of 15 meters (a touch over the 16 yards given), assuming an optimal 45 degree takeoff, implies a launch velocity of about 13 yards per second. Not sure whether to use that velocity, or the rate at which the trajectory covers horizontal ground - more like 9 yards per second - for the Slam, but at least it's closer.

I conclude that the Super Jump rules as given are pretty much aphysical, but I'm not sure I have a clean alternative to offer. I know range of the jump goes as the square of the takeoff velocity, so maybe it should be something as simple as Basic Move^2/5 for a running start, half that for a standing jump.

Last edited by vitruvian; 01-13-2012 at 08:12 AM.
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