Does Rope Trick create an extradimensional space, or does the space already exist?

Question

In my answer to this question, I used the fact that Rope Trick states

...an Invisible entrance opens to an extradimensional space that lasts until the spell ends.

After thinking about it for a while, I started to wonder if I was wrong. This sentence can be taken two ways - either the entrance lasts until the spell ends, or the extradimensional space lasts until the spell ends.

The text

Anything inside the extradimensional space drops out when the spell ends

implies that the space ceases to exist when the spell ends. But this is different from similar destruction of bigger-on-the-inside spaces, such as the Bag of Holding:

If the bag is overloaded, pierced, or torn, it ruptures and is destroyed, and its contents are scattered in the Astral Plane.

But another spell, Mordenkainen's Magnificent Mansion functions incredibly similarly to Rope Trick, where anything left inside will be ejected when the spell ends... This may be a difference between spells and magical items that do similar things. So this question could easily apply to MMM too.

I do not believe that the answer to this question doesn't matter. For example, Thomas Markov's question could get a clearer answer with the answer to this question. For example, a creature within the space gets banished, and the spell ends before the creature comes back. If the space still exists, it could be that the creature ends up back in the space without getting ejected, since that only happens at the time of spell-end, effectively trapping the creature. On the other hand, if the space does not exist any longer, who knows what would happen? (Hence the question by Thomas Markov). And, if these kind of spaces apply to magical items as well, it is very related to the question I referenced above, as well as this one linked by Someone_Evil.

Taking the English meaning, if I say "A hole is cut in a wall 2 feet wide", the subject of the sentence is the hole. It's not the wall that's 2 feet wide, it's the hole. Similarly, it can be read that the entrance is the subject of the sentence, which is the thing that lasts until the spell ends. But, it could also easily be said that the only reason the entrance exists is because the space was created...

So... Does the space get created and cease to exist when the spell ends, or is it the entrance?

Answer 1

The text is not clear on whether you're magically opening an entrance to a pre-existing space, or magically creating a space and then opening an entrance to it. But the spell is, in general, vague on the details. For example, rope trick does not specify what the space is like on the inside -- whether the environment is exactly like what's right outside, what sort of surface you're sitting on, what the "walls" of the space look like (other than the small window out), or whether there are any features, such as rocks or furniture, that belong to the space itself. It's really up to the DM, and potentially the spellcaster, to determine how this should function. (Compare this to demiplane, which goes into some detail about what the demiplane is like inside.)

I'm not sure there's actually much of a functional difference between the two options. In either case, everything inside gets swept out when the spell ends, and the spell does not specify that anything exists inside the space (though it doesn't actually say it's empty, either), so presumably it's functionally empty when you first enter it. There may be some edge cases as you described, but I'm not sure there needs to be a clear rules-based answer -- that seems like the sort of thing the DM should just decide on the fly if and when it actually matters.

Personally, I read that text to mean the space itself lasts until the spell ends, and the entrance ceases to be an entrance at that point. I would interpret that the spell itself is folding space at the top of the rope to create a pocket of reality that doesn't quite make sense with the world outside, but is effectively part of that outside world in terms of lighting, temperature, and materials. If you're casting from on top of a glacier, the area inside the rope trick is going to be something like an ice cave, a piece of glacial surface twisted up into a room that will get you out of the wind but doesn't stop you from being in basically sub-zero temperatures.

But that said, other media examples of similar concepts aren't much clearer. When Doctor Strange pulls a battle into the Mirror Dimension, is that an actual separate dimension to the side of reality, or is it creating a sort of bubble of twisted space? It isn't very clear, and it doesn't actually matter.

As far as the comparison to a Bag of Holding goes, I don't think it actually matches up to breaking the bag, which is what results in catastrophic loss. Rather, the ending a rope trick spell should probably be seen as analogous to turning a Bag of Holding inside-out, which similarly causes all the contents to dump out at your feet. That fits well with the idea of rope trick as a space-bending spell -- when the spell ends, the 'pocket' of space you made just straightens back out, forcing any contents out in the process because the bent space they're in is returning to 'flat'.

Answer 2

A very technical reading of the spell actually implies the the space vanishes while the entrance remains, but likely refers to both the entrance and the space itself.

Rope Trick says:

You touch a length of rope that is up to 60 feet long. One end of the rope then rises into the air until the whole rope hangs perpendicular to the ground. At the upper end of the rope, an Invisible entrance opens to an extradimensional space that lasts until the spell ends.

In this case, lasts until the spell ends is not exclusive to either the entrance nor the space, and both last until the spell ends. If it were only the entrance that went away, while the space remained, then it would probably be worded more like this:

You touch a length of rope that is up to 60 feet long. One end of the rope then rises into the air until the whole rope hangs perpendicular to the ground. At the upper end of the rope, an Invisible entrance that lasts until the spell ends opens to an extradimensional space.

I think we can safely discard the idea of the entrance remaining while the space goes away right off.

As for the difference between how Rope Trick functions and how a Bag of Holding functions, you can likely chalk that up (in universe) to being a built-in safety feature for the spell, or (out of universe) to prevent cheese with exceptionally cheap and low level access to the Astral Plane

One last note, Conjuration spells don't only pull something from somewhere else, they also create things from nothing, such as in this case or in the case of Mordenkainen's Magnificent Mansion.

Conjuration... Some spells summon creatures or objects to the caster’s side, whereas others allow the caster to teleport to another location. Some conjurations create objects or effects out of nothing (Schools of Magic; Basic Rules, Ch. 10/p. 84)