Can Shape Water be used on Watery Sphere?

Question

The 4th level spell Watery Sphere creates an area of water as the name suggests:

You conjure up a sphere of water with a 5-foot radius at a point you can see within range.

To my understanding, a 5ft radius centered on point takes up 4 squares on a grid.

The cantrip Shape Water allows you to manipulate an area of water:

You choose an area of water that you can see within range and that fits within a 5-foot cube. You manipulate it in one of the following ways:

The effects include freezing the water, animating it, changing its flow and changing its color.

The spell affects water that can fit in a 5ft cube, which Watery Sphere is larger than. Shape Water specifies that if there are creatures in the water being effected, you cannot freeze them in it. But if for whatever reason you wanted to cast Shape Water on part of a Watery Sphere, would you be able to?

To clarify, I am not only asking if you can partially affect the spell despite it not fitting perfectly into a 5ft cube, but also if the Watery Sphere's water can be targeted by Shape Water at all, I think the answer to that would be yes because the spells description states the Watery Sphere is comprised of water, and thus would possess all the properties of water?

Answer 1

Yes, with an understanding DM

The first hurdle is whether or not the "water" of watery sphere is normal water. Most would say yes, but best to check ahead of time.

Assuming the DM agrees that it's water than can be affected by shape water, you have options

You quoted the relevant parts, reported below (emphasis mine):

You choose an area of water that you can see within range and that fits within a 5-foot cube.

The spell states that the area chosen must fit within a 5-foot cube, but it does not need to be a 5-foot cube. In other words, the caster can state they they only want to affect a 1-foot cube. Or a 2x3x3 rectangle. Or a pole that is 8.66-feet long (5ft * √3 = corner to corner). Whatever you are affecting does not need to be the entire volume of a 5-foot cube. So long as what you have planned fit entirely within the sphere, you're good.

The only thing you could not do is freeze the water as the spell states, "provided that there are no creatures in it." So if you're restraining someone, that counts as a creature. Or at least, you could not freeze center mass. But you could probably freeze a section away from where the creature is/creatures are being held.

Answer 2

No, by a strict reading of the rules.

You quoted the relevant parts, reported below (emphasis mine):

You choose an area of water that you can see within range and that fits within a 5-foot cube.

First of all, the spell description refers to an area, not to a volume. Sometimes, the two terms are interchangeable in DnD spells: in this case, it is not unreasonable to consider as a target for the cantrip both areas (e.g., a puddle) or volumes (the water in a bottle).

The most direct way to interpret the above description is that the targeted area must entirely fit in a 5ft cube: since Watery Sphere spell creates a volume larger than a cube with a side of 5ft , such sphere can not be targeted by the cantrip.

A more loose reading allow targeting portion of larger areas/volumes.

Another way to interpret the spell description is that the area/volume can be a part of a larger portion of water: in this case, the caster would be allowed to target up to a quarter of the sphere created by the Watery Sphere spell, provided other requirements are met, for example there are no creatures inside that quarter for the freezing use of Shape Water.

Anyway, beware that such interpretation may induce some consequences that should be considered: for example, is a creature allowed to take the frozen part of a Watery Sphere away?