[Quick!] Need help, what is the max distance one falls in a round?

[Esiminar]

I know it's a bit late, but to bring this back on topic.

I have a table that lists how fast and how far you have fallen in vacuum.

Time(s)	Speed(m/s)	Distance(m)
0	0		0
1	10		5
2	20		20
3	30		45
4	40		80
5	50		125
6	60		180
7	70		245
8	80		320
9	90		405
10	100		500
11	110		605
12	120		720

Terminal velocity for an average human with arms and legs spread is about 55 m/s

So converting that into feet

Time(s)	Speed(ft/s)	Distance(ft)
0	0		0
1	33		16
2	66		66
3	98		148
4	131		262
5	164		410
6	197		590

Terminal velocity: 180 ft/s
You reach terminal velocity in about 5½ seconds having fallen 500 ft, in the last half a second of the round you fall a further 90 ft.
Giving a total of 590 feet fallen in the first round.
Every round after this you fall a further 1,080 feet.
This is all assuming you are the same weight as an average human and falling as a skydiver however.

If you want speeds for an un-braked fall the "Storm Lord's Keep" 670 ft. in the first round, 1,150 feet in subsequent rounds is probably a good average.

 

[Lela]

I know you don't like puny members telling you what to post and not to post (and I agree, to a point), so know that I don't mean this that way.

But I hope you aren't dismissing what AuraSeer said. People do come to this forum to get help on rules they don't understand and you do need to be careful how you say things. If you do it differently than the books then say so. But make it clear it's IYC.

While this one is on the edge (as you see it), this rule of courtesy still applies. While it's unoffical (as far as I know), that's how this forum survives. You're just being asked to respect that, not change your thinking.

 

[rhammer2]

My rule of thumb on this type of situation is that momentum is conserved within the framework of the spell.

If you are falling, you are still falling. If you are still you are still not moving when you come out of the teleport. You ignore momentum caused by the framework of the external universe, so you can safely teleport to the moon or to the far side of the planet.

The spells do not give the DM or character any guideline on how to do this, so any ruling will be a house rule.

Constructive response.

If we're conserving momentum, what happens when you teleport to the opposite side of a rotating spherical world?

To me, it makes more sense to allow someone to Dimension Door to safety while falling than it does to open the Physics can of worms.

-Hyp.

 

[Mark Chance]

While it's unoffical (as far as I know), that's how this forum survives. You're just being asked to respect that, not change your thinking.

And I understand that completely. I understood what Auraseer was saying. My only objection was what seemed to me something akin to being called a liar.

You, OTOH, provide an admirable example of how easy it is to be reasonable rather than dictating to others what their actual intentions were.

To assist all of those people are convinced that they can read my mind and therefore know that I was committing something akin to a cardinal sin, I'll go back and edit my original post.

 

[andargor]

If you are using the interpretation that velocity/momentum is preserved when you Dimension Door, then the character could opt to exit sideways (i.e. parallel to the ground) to minimize damage...

Andargor

 

[totoro]

Teleportation and conservation of momentum

Choose the one you like (keep in mind that in most cases, teleport other becomes a deadly weapon):

1) It's magic, so don't worry about it. You land where you want after you teleport, unmoving. This seems to be the default rule, works just fine almost always, but is perhaps not realistic since "unmoving" is relative.

2) Momentum stays the same from your original frame of reference. This one is tough. If you teleport to the other side of a rotating world, the shock of arrival would have lethal consequences. This one works just fine for dimension door.

3) Momentum conforms to new location. If you were falling down and teleported to the other side of the world, you continue falling down, even though the momentum from your original frame of reference implies you would "fall" up. If you want to make this sound like if comports with physics, you could say momentum is related to gravity. In other words, if you teleport from one side of a gravity well (e.g., the world) to the other, your momentum is the same relative to the gravity well. I like this one. There is an issue of teleporting into a void (no nearest gravity well), but it doesn't matter how fast you are going in a void, so who cares?

3.5) Teleport doesn't let you teleport into a void. You need plane shift or something like that.

4) Your momentum changes direction as you wish. If you teleport to the ground after reaching terminal velocity, but point your momentum up, you will fall into the air and land a bit more comfortably when you crash back down to the ground. This allows you to teleport across the world by matching your momentum to the spin of the world. This one could create some unforseen problems with dimension door and others with imaginative players.

4.5) You can pick your momentum. This makes your original momentum meaningless. You are going as fast or as slow as you like. This would allow you to use dimension door to "charge" without running the requisite distance. It seems is even easier for imaginative players to exploit this rule. How about teleporting a boulder that is travelling at, say, near light speed, onto a city? That would make teleport object the most powerful spell in the game. I think this is a bad rule (as is rule 4), but some may like it.

5) Exactly as physics as we know it dictates. Oh, look at the time.... Maybe I'll finish this later.

 

[magnas_veritas]

If you are using the interpretation that velocity/momentum is preserved when you Dimension Door, then the character could opt to exit sideways (i.e. parallel to the ground) to minimize damage...

Or, possibly, even exit going up, cancelling out a lot of the momentum once gravity kicks in. At best, you're prone, and at worst, you fall from (say) 20-30 feet (as you go up until your momentum is overcome by gravity, and are then pulled back down).

* Edit: Or, exiting parallelish to the ground, use that to make one heck of a bull rush.

Now, of course, it's vastly simpler to just assume that momentum is cancelled out using such magics, as (I imagine) very few people find doing the math to be fun.

Brad

 

[Hypersmurf]

Or, possibly, even exit going up, cancelling out a lot of the momentum once gravity kicks in. At best, you're prone, and at worst, you fall from (say) 20-30 feet (as you go up until your momentum is overcome by gravity, and are then pulled back down).

... with the problem being that by the time you get pulled back down, that same gravity that slowed you down has sped you back up to... well, pretty much the exact speed you were originally falling at, just in time to hit the ground...

-Hyp.

 

[Azul]

Re: Teleportation and conservation of momentum

Choose the one you like (keep in mind that in most cases, teleport other becomes a deadly weapon):

3) Momentum conforms to new location. If you were falling down and teleported to the other side of the world, you continue falling down, even though the momentum from your original frame of reference implies you would "fall" up. If you want to make this sound like if comports with physics, you could say momentum is related to gravity. In other words, if you teleport from one side of a gravity well (e.g., the world) to the other, your momentum is the same relative to the gravity well. I like this one. There is an issue of teleporting into a void (no nearest gravity well), but it doesn't matter how fast you are going in a void, so who cares?

I love physics and all too, but this is a fantasy game. I think option 3 here is the most reasonable compromise. "Fantasy physics" that seem to apply in D&D, especially in regards to magic seem to be far more simplistic and based on one's current perceived frame of reference rather than any more realistic physics. Hence, if you teleport while standing still, you are standing still at the other end. All of the complex realities of planetary rotation and other messy physics are ignored. Everything revolves around reality *as the characters would perceive it* rather than as real-world physics dictates it would be. Subjective physics rather than objective physics, so to speak.

Option 3 seems to strike a nice balance between appearing to preserve momentum which viscerally feels right, at least to me, and helps avoid some truly grotesque abuses of the game system - e.g. put a parachute on a blink dog (to reduce his terminal velocity to less than his maximum dimension door distance) and he could dimension door his way into orbit and back (well assuming he could tolerate the vacuum - if there is a vacuum in your world).

Sure, you can buy yourself a "safe" round by teleporting/dimension dooring upwards, but you will have built up speed in the process which will put you in a world of hurt when you zot back down (nothing a feather fall can't fix, but still). Each action has a reaction but the logic of it is kept simple.

The reason I like this solution is because it preserves *perceived* momentum (which feels right in the simplified physics of the D&D magic system). Yeah, it's little more than a house rule or an opinion, but to my mind, it fits, causes the least headaches and is the most resistant to abuse by munchkins who try to abuse game mechanics.

Allowing someone to select their velocity upon teleporting/dimension dooring is a recipe for disaster... Imagine a high level wizard/sorcerer teleporting up 100 km over a population center with a big chunk of something dense and heat resistant and a shapechange (to something immune to fire) spell on himself - he sets his velocity to meteor strike speeds (say 10km/s)... his immunity to fire lets him ignore reentry burn and he teleports away after 1 round... to somewhere else (far away) at zero velocity relative to the ground.

Here's the catch... There is still that large (50lbs per level of additional stuff can be teleported with the caster... so about a 1/2 ton rock at 20th level) rock hurtling down at 10km/s and about to hit that population centre (probably an enemy city or fortress) with an impact so great that it might well produce a mushroom cloud. Impact is in about a round. Damage and area of effect for that much kinetic energy hitting the earth is off the scale.

That kind of devestation is simply far beyond anything any 9th level spell should be capable of doing.... let alone what a 5th level spell should be capable of... it's well into the epic spell range (and I think calling down a city-wrecking meteor would be a doozy of an epic spell ).

Now, think about all the evil outsiders who are immune to fire damage (which re-entry style burnup would be) and can teleport without error at will. These beings have every motive to use any bulky object as a pseudo-meteorite in combat. Who cares about the 1/day Meteor Swarm ability of a pit fiend when it can do THAT over and over and over until it gets bored and the kingdom it is fighting is little more than a crater-pocked moonscape?!

Maintaining true velocity relative to a planet (let alone the galaxy or universe in a setting which allowed travel between worlds) would of course simply splatter the teleporting mage against the first surface he impacted (pretty much as if he was shot out of a cannon).

Repeat after me - real world physics and reality warping magic don't mix.

 

[AuraSeer]

Thanks, I just won $10 in a bet by predicting your exact response.

*plonk*