Minus Wall of force contained high CR swarms.
Dude, it's "Three Faces of Evil"; it's deadly enough without me throwing in stuff that Mearls didn't originally include.
If they try the same cheese in "The Spire of Long Shadows" (levels 13-14) though, then all bets are off.
I think you might be over thinking it. The spell says the window looks through the extradimensional space. It would be centered on the rope because the rope goes through that space when the spell is cast. There is nothing in the description that would give me any reason to think the window is mobile.
I disagree. From SRD, p.173:
"At the upper end of the rope, an invisible entrance opens to an extradimensional space that lasts until the spell ends."
"The rope can be pulled into the space, making the rope disappear from view outside the space."
"[T]hose inside can see out of it as if through a 3-foot-by-5-foot window centered on the rope."
Maybe I'm being too literal, but the first statement suggests that the rope doesn't actually enter the space -- the entrance opens 'at the upper end', not once the rope enters the extradimensional space. The rope can be pulled into the space, which means if the upper end of the rope isn't fixed outside the space, it is mobile, and regardless the rest of the rope can be played out as desired within the space. The spell says the window is "centered on the rope", not "centered on the upper end of the rope". Had the designers intended for the window to be synonymous with the entrance, they could have just said that -- "those inside can see out of it as if the invisible entrance were a 3x5 window". (That's how I'll be ruling it from here on out.)
This is probably just a good example to use on why not to excessively parse the language of spell descriptions in 5E. If there isn't a consistent interpretation on how a given spell works, then it's really hard to say that a spell is 'the best 2nd level healing spell in the game', for example. ; )
The way we play in my group, is the spell sets the parameters, but the player can fill in the non-mechanical stuff. The spell says that the space can fit 8 medium creatures, so anything that makes sense with that should be fine.
In theory, yes. In practice, if the spell has a more powerful higher level version, then being loosey-goosey with how useful the lower level spell is might well invalidate one or more reasons for the higher level spell to exist. In the case of Rope Trick, that spell is Magnificent Mansion (not Private Sanctum, as Private Sanctum doesn't create an extradimensional space). Magnificant Mansion creates an extradimensional space with a maximum size of 50 10-foot cubes, with a portal that can be opened and closed (and is invisible when closed) and can only be entered when open by specific creatures designated by the caster. It contains a staff of 100 invisible servants and enough food to feed 100 guests a nine-course meal. This seems like an awful lot, but when compared to your interpretation of Rope Trick, it's not really that much more from a mechanical aspect -- both spells would create an environment that appears as the caster wishes, both are as spacious as the caster desires (but Rope Trick doesn't expressly have a maximum size, only a maximum capacity). The Mansion has up to 100 servants, but they can't do anything the PCs couldn't do for themselves and are expressly prohibited from taking actions that would harm another creature. So mechanically, the difference between Treantmonk's Rope Trick and Mordenkainen's Magnificent Mansion are as follows:
- the Rope Trick entrance must be within 60 feet of the caster, while the entrance to the Mansion can be within 300 feet (there might be situations where this can make a difference, but nothing obvious comes to mind)
- the Rope Trick can be entered by any creature that can find its entrance as long as it can fit in the space, while the Mansion can only be entered by designated creatures
- characters in the Rope Trick must eat their own food supplies, while the Mansion provides food
- the Rope Trick lasts an hour, while the Mansion lasts 24 hours (Rope Trick is thus only useful for short rests, while the Mansion can be used for short or long rests)
Magnificent Mansion is a 7th level spell, while Rope Trick is a 2nd level spell. I'd argue that the mechanical differences between the two spells as described above do not justify that difference in spell level, and that the remaining difference must be made up by the non-mechanical 'flavor' aspects of the spell which are treated as trivial in the Treantmonk version of the spell. The counter-argument is that Rope Trick should be higher level (say 3rd), while Magnficent Mansion should be lower (say 6th), which would bring the spells closer into line with their mechanical differences, but this presupposes that the designers set the spell levels with that distinction in mind and sharing the idea that non-mechanical distinctions are of no value in determining spell power.
This is a fallacy, and to the end of proving that fallacy, I present Pauper's Paradox of Spell Power.
A spellcaster invents a new spell and calls it God's Decree. The spell gives the caster the power to change any one fact about the world, but it cannot change the game-mechanical expression of that fact. So, for example, the spell, if cast on a rope, could change the color of the rope, or whether the rope feels cool or warm to the touch, but it could not cause the rope to deal damage to anyone holding it, or change the DC required to climb it. The spell could even change the appearance of the rope, making it appear to be made from twined grain stalks or even water, but the rope's hit points would not change.
Most of you would recognize this as a super-charged version of a number of existing cantrips in the game: Prestidigitation, Druidcraft, Thaumaturgy, et al. Since the spell makes a permanent change and is not restricted in the classes of changes it can make, it is clearly superior to those similar cantrips; there would be no reason to cast one of those cantrips when you could cast God's Decree instead, so it's clearly more powerful than a cantrip. However, since the spell cannot effect a game-mechanical change within the game world, most optimizers would argue that it, at most, is a first-level spell, and many would probably argue that it's even weak as a first-level spell; why cast this spell when you can cast a spell like False Life or Shield that does have a game-mechanical effect?
Thus the paradox of treating as valueless things in the game that can't be expressed in mechanical terms. My own belief is that God's Decree would be a minimum 4th level, probably 5th level spell, based solely on its effectiveness compared to Major Image, a 3rd level spell that mimics a large subset of God's Decree's effects but has limited range and duration by comparison. It's less powerful than Wish or even Limited Wish, which can incorporate mechanical changes, so it's max 6th level. And in the hands of the right player, this spell would be far from valueless.
Not to keep beating the zombified horse, but that paradox is yet another reason I disapprove of optimization as a playstyle and/or philosophy of play.
--
Pauper