Is momentum conserved when teleporting?

[Terramotus]

Not that, to my understanding, there's an actual rule on this. I was just curious how the rest of you handle things.

On one hand, if you declare momentum is not conserved, Eladrin can freely jump off of buildings/cliffs/whatever, readying an action to teleport to the ground just before they hit the ground.

On the other hand, if you declare momentum is conserved, the PCs can totally ruin the day of flying creatures by teleporting them in front of walls, and do bizarre things to get to places they wouldn't have been able to otherwise. They could also, potentially, do suicidal human cannonball attacks.

Personally, I allowed momentum to be conserved. I really don't want teleporters to be immune to falling damage, and I like having oddball uses of powers.

 

[Abisashi]

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.

 

[Rafe]

I would say it's conserved, I guess. What what I understand of teleportation in 4e, it seems more like dimension door than old-school teleport, at least in terms of fey step.

 

[frankthedm]

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.

That's why the game has a DM. The DM simply says "You keep your falling momentum when you teleport."with a firm planting of the foot. No muss, no fuss, no world implosions & no PCs becoming red jelly except from terminal velocity falls.

 

[James McMurray]

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.

Why? I don't recall any rules about planetary rotation.

In our paragon campaign the GM ruled that momentum was lost. I would rule the other way. However, there is no risk of killing dragons by teleporting them next to walls, because there is no movement outside of your own turn, and no turning radius limitations. On the dragon's next turn he can just fly somewhere else.

 

[Caliban]

Momentum is stored until you piss off the DM. Then you get it all back at once. Go ahead. Teleport. I dare you.

 

[small pumpkin man]

Powers assume your momentum is preserved. Rituals don't. It's simple, and it gets rid of most annoying issues while allow players to fiddle around with things if they feel the desire. It also meshes with most descriptions (Except for Arcane Gate, Wizard Utility 10, but that's it's own deal.)

 

[trayburn]

On one hand, if you declare momentum is not conserved, Eladrin can freely jump off of buildings/cliffs/whatever, readying an action to teleport to the ground just before they hit the ground.

For the record, by the rules, this wouldn't work for reasons unrelated to momentum preservation. A readied action uses a standard action to prepare an action as an immediate reaction (PHB 291). This means that your action would go off after the intended action (plummeting to your death) not before.

Further, even if you can concoct a trigger condition that works like "I'm 10 feet off the ground" or the like, you have another problem. All falling is instantaneous in 4e (phb 284), you also cannot take an immediate action during your own turn (phb 268, last sentence under "Once Per Round").

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.

 

[malraux]

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.

 

[Mort_Q]

Powers assume your momentum is preserved. Rituals don't. It's simple, and it gets rid of most annoying issues while allow players to fiddle around with things if they feel the desire. It also meshes with most descriptions (Except for Arcane Gate, Wizard Utility 10, but that's it's own deal.)

Nice. I can use that.