# What happens if you drop a 30-foot cube of water from a height of 30+ feet on someone's head using the Create or Destroy Water spell?

In D&D 5e, what would happen if you dropped a 30-foot cube of water from a height of 30 feet (or more depending on elevation and positioning) on someone's head, using the Create or Destroy Water spell?

• Hey, welcome to Role-playing Games! Take a look at our tour. Hopefully this question has an answer, and if not, maybe it can be adjusted to be answerable. Welcome again, and have fun. Commented Jan 17, 2022 at 19:01
• FWIW, in real life the initial impact would be equivalent to jumping head first into water from a height of 30ft, i.e. not too bad if you're ready and braced for it. However, depending on local terrain and exactly where you happened to be standing relative to the falling water cube, you'd probably then be swept off your feet by a torrent of water spreading in all directions after hitting the ground, and might get thrown against a solid obstacle or pummeled by debris picked up the water. Not recommended. Commented Jan 18, 2022 at 1:29
• @IlmariKaronen the difference here is falling water will have been affected by the airflow as it falls, possibly breaking the surface tension already. So it wouldn't be exactly the same as falling into a still water. Commented Jan 18, 2022 at 10:12
• I was going to suggest making it frozen or just under boiling for additional effect, but apparently the part I am remembering about the temperature being up to the caster is from another edition, since this one doesn't seem to say anything like that. Commented Jan 19, 2022 at 16:54
• in physics terms? The person gets wet. 30 feet (~9 meters) or 1000 feet - water falling in liquid form doesn't kill people Commented Jan 20, 2022 at 16:54

### Create or destroy water doesn't do that.

The spell description of create or destroy water states (PHB, p. 229; emphasis mine):

Create Water. You create up to 10 gallons of clean water within range in an open container. Alternatively, the water falls as rain in a 30-foot cube within range, extinguishing exposed flames in the area.

It makes it rain, which does zero damage.

In addition to @Thomas Markov's excellent and correct answer: even if it just raining weren't spelled out explicitly, spells only do what they say. This means that, unless explicitly spelled out, a spell's effect will not do any damage whatsoever.

That's why some of the world-manipulating spells have concrete mechanical effects on monsters/NPCs/PCs spelled out: because otherwise you cannot obtain any mechanical benefit from a spell in combat by the rules as written. That applies especially with regard to damage.

• My issue with this answer is that "spells only do what they say" is only half the equation. The other half is "and anything else is left up to the DM." Practically every time this "wisdom" shows up on RPG.SE, it shows up with only the first half. DMs should never feel constrained to adjudicate spells mechanistically at the expense of the narrative, which is what answers like this imply. Spell descriptions are a floor on what a spell does, not a ceiling. The ceiling is up to the DM. Commented Jan 18, 2022 at 22:23
• This is true as well, but for DM fiat there is no need to ask this page, or the internet, because only the DM's opinion matters in the slightest. That's why my answers here are far more RAW-centric than when I play myself or talk to people I play with IRL. But yeah, an important reminder that the rules are mere guidelines how the game can be played, there's no RAW-police irl Commented Jan 19, 2022 at 9:43
• For my money, the "anything else is up to the DM" piece is RAW. It's just another way of phrasing #3 under "How to Play" in the PHB: "The DM narrates the results of the adventurers’ actions." Or as the DMG puts it on page 1: "The D&D rules help you and the other players have a good time, but the rules aren't in charge. You're the DM, and you are in charge of the game." As for whether this point has a place on RPG.SE, I emphatically say yes. DMs who want to run a good game -- who want to know how best to use their fiat powers -- should be able to get good guidance here. Commented Jan 19, 2022 at 16:10
• FYI, there's an excellent discussion of this whole issue on Meta: Shouldn't we move past repeating "rules do what they say and nothing more?". Commented Jan 19, 2022 at 16:11
• That said, there's a massive difference between "10 gallons of water distributed within a 30-foot cube", and "a 30-foot cube completely full of water" (as OP seems to imagine). DM fiat normally does not cover a factor of ~20,000 in effect size. Commented Jan 19, 2022 at 22:56

Here's what the rules say:

Create or Destroy Water
1st-level transmutation
Casting Time: 1 action
Range: 30 feet
Duration: Instantaneous
You either create or destroy water.
Create Water. You create up to 10 gallons of clean water within range in an open container. Alternatively, the water falls as rain in a 30-foot cube within range, extinguishing exposed flames in the area.
At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, you create or destroy 10 additional gallons of water, or the size of the cube increases by 5 feet, for each slot level above 1st.

You're asking what happens beneath the cube when you use the alternate form of create water. The rules say open flames are extinguished, but don't specify beyond that, so lets think it out.

The rules indicate that you're creating 10 gallons of water in a 30ft (27,000 cu. ft or ~20k gal) cube, either over 6 seconds or instantaneously (the rules say the latter). This is the equivalent of throwing two large buckets of water into a fairly large area. Things will get wet, but not drenched. Bare dirt or stone might become slick, but grass or wood would not. An embankment might become very difficult to climb. A guard might be distracted (although their vision would not be obscured).

If a GM were to rule that this makes the area slick, compare to the Grease spell. Grease is also 1st-level. It affects a 10-ft square, creates difficult terrain, and introduces a save-or-fall-prone effect. It would be logical for Create Water to act like Grease with a larger area and longer duration, but very limited terrains it would effect. My gut says that difficult terrain and save-or-fall-prone is appropriate for a wetted dirt road, while only difficult terrain is appropriate for stone. Sand or grassland would not be any harder to traverse.

To me that feels like a creative use of the spell, rather than a munchkin-y exploit.

Casting at higher levels allows you to create 10 gallons across a larger area (70-ft cube at 9th-level) or create more water in a 30-ft cube (90 gal. at 9th). 90 gallons is enough to get things in the area pretty wet, but not enough to deal damage. I would be very hesitant to expand any Grease-like effects with higher casting. Grease does not change when cast at higher levels, and I think that's intentional.

You asked what could be two different questions.

1. What happens when you use the second option in Create Water. That was answered.
2. What happens when you (however you do it) create a 30-foot cube of water 30 feet above someone, then let it drop.

You cannot do that with Create Water (at any level), but you could do it with much higher-level spells, not least is Wish or some sort of portal to a water plane.

1 cubic foot of water is just under 7.5 gallons, which is just under 62.5 pounds. A cube of water 30-feet a side is 27,000 cubic feet, or 302,500 gallons, or a little under 1.7 million pounds (roughly 843 tons). If that were to fall on people, it would wash them away. It would likely wash away anything including giants and dragons. That's literally 360 inches of rain in 6 seconds. Because it's "just water," it won't necessarily cause any damage, but it will likely cause blunt-force damage by smashing creatures into walls and trees and stuff. The water will likely cause a flash flood in whatever direction is down (and most towns were built on hills). This amount of water will damage houses, break down doors (which were often flimsy if unlatched), rip up small trees, and create a huge mess.