Is a creature in the area of a Wall of Water spell trapped in ice when hit by the Ray of Frost cantrip?

Question

In 5th edition Dungeons & Dragons, I am playing a Sorcerer where I have set myself the rule that I can never take fire spells, and instead take weaker spells and try to make the most of them with creativity. I am wondering if the following trick works.

The Wall of Water spell has the following wording:

Spells that deal cold damage that pass through the wall cause the area of the wall they pass through to freeze solid (at least a 5-foot square section is frozen).

If I use the Quickened Spell Metamagic option and cast Wall of Water into a creature's space as a bonus action, then as an action cast a Ray of Frost cantrip at the creature, will that freeze the water and trap the creature inside a block of ice?

Answer 1

Frozen

This is a great combination! The rules for casting two spells with a bonus action and action simply state (PHB, 202):

A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven’t already taken a bonus action this turn. You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action.

In your example, you have used your Bonus Action via Metamagic to cast Wall of Water. There is no save for wall of water; it only creates battlefield control aspects within its area.

Should you cast it on a space containing a creature, that creature would be within the Wall (although do note the Wall is only 1' thick.) Also note that only the 5' section of the wall they are in (see below) is turned to ice (and if destroyed, does not refill with water.)

The creature is now in 1' of water and the follow-up Action Cantrip of Ray of Frost interacts beautifully with Wall of Water's cold damage response:

Spells that deal cold damage that pass through the wall cause the area of the wall they pass through to freeze solid (at least a 5-foot-square section is frozen). Each 5-foot-square frozen section has AC 5 and 15 hit points.

You'd now have a Wall of Water with a frozen section containing a creature in their 5' space (but only 1' thick of ice.)

But what can a frozen creature do?

This is going to likely get table-dependent. There are no rules with regard to being 'in ice' and what conditions that imposes (like Restrained or Grappled.)

How I'd rule

I'd likely give a Dexterity save to avoid the ice (DC set by the caster, much like with Wall of Stone trying to entrap someone) and then upon failure give them the Restrained condition.

Answer 2

Yes, this should work. You'd cast Wall of Water in such a way that the creature is inside the wall. Then you'd cast Ray of Frost on that creature, freezing the 5-foot square section around it (which is 1 foot thick).

From the Wall of Water spell description:

Spells that deal cold damage that pass through the wall cause the area of the wall they pass through to freeze solid (at least a 5-foot-square section is frozen). Each 5-foot-square frozen section has AC 5 and 15 hit points.

Note that Ray of Frost must target a creature, so you can't for example point your ray upward to freeze a 10-foot pillar above your target (unless there's another creature there to target).

Ray of Frost (PHB 271):

A frigid beam of blue-white light streaks toward a creature within range. Make a ranged spell Attack against the target.

I'd rule that if your Ray of Frost hits, the creature captured in the ice is Restrained, and can break the ice around it by hitting the wall section's AC (which is 5) and dealing enough damage to destroy it (it has 15 hit points).

It doesn't restrain strong enemies for very long, but if I were your DM I'd give you Inspiration for this kind of thinking.

Answer 3

Ray of Frost may not freeze the whole wall, but could still freeze enough of it!

As you state in your question, for Wall of Water:

Spells that deal cold damage that pass through the wall cause the area of the wall they pass through to freeze solid (at least a 5-foot square section is frozen).

Given that Ray of Frost doesn't have an area of effect (Line, Cone, Sphere etc.) but instead has one target it will not pass through a large area of the Wall of Water.

As you need a clear path for spells to travel, the spell will travel through the wall of water and freeze the minimum amount (at least a 5ft square section) however it would likely not freeze the entire wall (as the wall is up to 30 feet long by 10 feet high)

Having said that, freezing the 5ft by 5ft section containing the target would likely be enough to have your desired effect of at least partially trapping them in ice!

Answer 4

Personally I'd say yes as the "physics" of the question makes logical sense. You are casting a freezing spell on a body of water which an entity is standing in. I'd say there are two ways to handle a controllable entity being frozen; they die or they need to make a check to break free. They'd die as a result of the water in their cells expanding and bursting the cell. See the effects of frostbite for more specific details. Inspiration for breaking free from being frozen can be drawn from the 5th ed spell Freezing Sphere:

Creatures that were swimming on the surface of frozen water are trapped in the ice. A trapped creature can use an action to make a Strength check against your spell save DC to break free.

The DC for breaking free can be copied directly from the spell or can be adjusted depending the DMs opinion of how frozen the entity is. For e.g., the Freezing Sphere spell completely envelops the target with the intention of trapping the target while your version can be viewed as a homebrew variant of it and may not do so. The extent is update for debate and is likely dependent on detailed the situation is described.

The sequence of actions will need to be checked in case there's some hidden wording/meaning that restricts it in some way. I cannot adequately answer this given my level of experience.

Answer 5

Spells do what they say they do. Wall of Water can't trap people.

The only effect that entering the space of Wall of Water has on a creature is that it's difficult terrain. If you freeze a space of the Wall of Water that a creature is located on, there will be no effect on the creature; it simply creates an obstacle that they'll need to move around. Presumably, the creature would either be on one side of the wall when it freezes or on the other; they can't get "stuck" inside it, though the space remains difficult terrain. If the spell could trap people, it would say that; since it doesn't, it can't.