Is momentum conserved when teleporting?

[RefinedBean]

So a long-jumping high-strength Eladrin barbarian with Great Leap can jump a...

(diceroll)

...[bleep]ing long distance. Ready the teleport for mid-arc and get an extra 5+ squares in there.

Nice.

 

[Engilbrand]

I would probably do it like they did in the movie Jumper. It's entirely as appropriate. You want to jump from a building and teleport at the last second and look cool, do so. You want to spin around real quick, teleport behind your enemy, and swing at his head, go for it.
Don't let the rules be the physics of the game world. Go with what would be cool given the circumstance. Saying that a PC jumping from a building immediateely hits the ground is rather ridiculous.

 

[GoLu]

So your Eladrin would find he is splattered. Personally I cannot find an example of where a situation of preserved momentum would come up, but I've been playing mostly heroic teir so there could be some Epic teir powers that could create such situations.

The best I've been able to come up with would be an eladrin near a cliff being ready with a teleport in case "that big guy over there attacks me". So the big guy runs up and shoves the eladrin off the edge and the eladrin's player is disappointed to learn that readied actions aren't interrupts.

Although in that case, the attack would be completely resolved before the teleport happened, which might arguably include falling damage from being shoved off the edge. I probably wouldn't run it that way, mind you, but I could totally see a case for it.

 

[Patlin]

It depends on your frame of reference, and if your frame of reference translates. If your frame of reference doesn't translate, teleporting large distances will always be instant death.

For example, if you don't use the planet you are on as a frame of reference, teleporting to a point far away on your planet will kill you because your momentum will be extremely large compared to where you teleport to.

If your frame of reference doesn't translate, what happens when you teleport between planes? Probably instant death.

I concur. In my campaign, you can teleport to or from a sailing ship without a problem, but jumping off cliffs is discouraged. Whether you want to call that frame of reference or DM fiat, I don't feel the need to accept either problem.

 

[deleteme123456]

So a long-jumping high-strength Eladrin barbarian with Great Leap can jump a...

(diceroll)

...[bleep]ing long distance. Ready the teleport for mid-arc and get an extra 5+ squares in there.

Nice.

Can't ready an action that will take effect during your own turn. (Well you can ready it, but it won't trigger because immediate reactions don't work on your own turn.)

 

[greatamericanfolkher]

I’ve never understood why people have such problems with letting players beam out of a fall. As far as my games are concerned, if they want to use a teleport like a high level feather fall, I have no problem with it.

 

[dinsdale]

For those interested in the momentum-is-conserved version of teleport (even including planetary rotation), I would recommend the book "The Witling", by Vernor Vinge. While it is far from his best work, there are some interesting ideas about the consequences of this.

For example:

- People teleport around the planet in boats, making short hops between lakes (to absorb the impact and provide a smoother decelleration)

- For weapons, they can teleport a small rock from a different lattitude, thereby giving it an impressive velocity relative to your enemy's position.

 

[Tale]

For those interested in the momentum-is-conserved version of teleport (even including planetary rotation), I would recommend the book "The Witling", by Vernor Vinge. While it is far from his best work, there are some interesting ideas about the consequences of this.

For example:

- People teleport around the planet in boats, making short hops between lakes (to absorb the impact and provide a smoother decelleration)

- For weapons, they can teleport a small rock from a different lattitude, thereby giving it an impressive velocity relative to your enemy's position.

Those consequences only exist if the rules of that world acknowledge Einstein. Newton, on the other hand, has much fewer complications.

 

[-Avalon-]

I would say that relative velocity is preserved. If you are motionless relative to the ground when you teleport, you're still motionless. If you are falling to the ground at 180m/s, you are still falling toward the ground at 180m/s. If a player had a unique way to teleport a dragon to directly in front of a wall, then I'd, as a one time event, let him roll something (probably wis/cha vs will) and pull damage from pg 42.

nerdy thought: you really don't want momentum to be eliminated when teleporting. If it did, then, since thermal energy is essentially atoms moving back and forth, you'd come out the other side with no thermal energy, ie at absolute zero.

extra nerdiness: not actually absolute zero b/c there'd still be potential energy, but you'd still come out with much less energy than you entered.

Very Extra Nerdiness:
How about this? Since walking is defined in some areas as simply falling forward... without any momentum you would either not be able to go through the portal, or you would successfully enter, but upon exiting, you would end up in a one particle thick sheet on the other side...

 

[Engilbrand]

I don't even pretend that the "laws of physics" as they exist in our reality exist in the D&D universe. If they did, magic and other neat things wouldn't exist. In a world like that, why would someone's speed always need to be conserved when they teleport? Let the person choose when it is. It will add an little extra thing to teleport abilities that can increase the cool of the game.