Portals: just how immobile?

[mkletch]

A character in my campaign has built a flying tower per Stonghold Builder's Guidebook. That much is kosher. He wants to add a portal to another location within that tower. The description of a portal (in SBG or FRCS) says that a portal is immobile. If the tower flies, will the portal move with it, or tear through the wall of the tower?

I ruled yes for the following reason: A portal is based on teleport w/o error. Even if it were based on teleport, the description of the room (for the error in a regular teleport) would not change if the room moved. This should then be even simpler with TwoE. So, even if the room moves, the teleport-based portal should be unaffected. It is tied to the room, not necessarily the exact physical location in three-dimensions.

Thoughts? Was this the right call? It would apply to any sort of stronghold with mobility.

-Fletch!

 

[Destil]

It's immobile with reguards to the surface / object it's created on, I'd say. Otherwise you'd need to worry about stellar motion & such.

 

[Kaji]

I agree with Destil. There's no compelling reason not to let the portal be in the tower and fixed to it's surface. I would let your mage be happy and portalized.

 

[Skwave]

Exactly. I think that all space/time spells and such are relative to themselves, rather than relative to the spacetime continuum.

Otherwise, if a portal was actually perfectly immobile, then it would actually appear to move after creation. The portal would not move, the planet rotation would actually cause everything else to move, except the portal. And, extrapolating all other movements of a planetary body : rotation of planet, movement of planet around solar body, movement of solar system through the galactic arm, movement of the galaxy through the universe, then the portal would appear to move very rapidly indeed.

Obviously, a mage creating such a item would probably consider that to be a failure and not a 'immobile' portal, although it would actually be so.

 

[Henry]

Wouldn't the creation of an item that is TRULY immobile destroy the planet you were on, or some such thing? Everything else relative to that item would be moving at tremendous speeds, n'est çe pas?

 

[AuraSeer]

A reasonable DM could rule either way. Real-world physics doesn't apply to D&D, so you can't assume things like orbital mechanics.

It's entirely possible for the game world to be an immobile sphere at the center of the universe, or a flat disk resting atop a fixed pillar, or anything else you can come up with. In such a situation, the DM could reasonably rule that portals are anchored to a specific point in absolute space, and are therefore truly immobile. Or he could say that they stick to the largest object in which they're embedded, and so could be placed in flying castles or sailing ships or whatnot.

Physical reasoning won't tell you how things work, because in D&D, "physics" is just another word for the whim of the DM.

 

[mkletch]

Physical reasoning won't tell you how things work, because in D&D, "physics" is just another word for the whim of the DM.

AuraSeer pretty much got my question. You almost can't open the PHB without hitting a page that defies the laws of physics as we know them. But, hey, it is fantasy, with magic, etc. From the few responses this has gotten, I figure that most/all agree with my decision, so I'll stick with it. Thanks.

Fletch!

 

[boothbey]

When in doubt about portals, just watch Stargate. Find a portal in Egypt, move it to the U.S. and it still works.

 

[Pax]

FWIW, I read "immobile" to mean "you cannot take it home as loot, no matter WHAT your carry limit is."

IOW, immobile in relation to it's original surroundings; they're built and enchanted on site, and don't mvoe from thats ite later.

However, if a Portal is located in a grat temple, which is in teh center of a huge city ... and said city later slides into the Ocean during a volcanic eruption and earthquake (shades of Atlantis, ofc) ... the Portal, if it remains physically intact, should still be operable.

Mind you, the GM can get creative, and either keep the exit point(s) relative to the Portal itself (meaning what USED to put you atop a nearby hill, now deposits you 200 feet above a field of large obsidian spikes ... or similar), or, that same portal might put you atop where the hill is NOW (especially appropriate in the case of reciprocal Portals). Some exit points may have had their corresponding structure obliterated, and may not function anymore. And so on.


...


So ... I'd say, as long as the Portal is affixed permanently to the wall/floor/wherever, it counts as "immobile" ... you can't come into the room, grab ahold, and walk out of the room, Portal in tow -- that's sufficiently immobile, IMHO.

And FWIW, I'd let theguy have a Portal in his mobile tower, that linked to a Portal in a nomobile location (a townhouse in the city, deep in a crypt, on the grounds of a temple of Mystara or Azuth (to whom the wizard has made large donations, presumably), or wherever else the wizard prefers to locate it).

 

[Death]

What about building a portal on a wagon and adventure with your own portal? Doesn't it sound a bit strange? Perhaps players would find a portal to some hidden underground place, decide, that this place would be fine hideout and try to bring outer portal with them...

They can remove floor too...