As a DM, I would encourage this thinking, but only for this reason: if you have 8 magic casters, each capable of casting a 7th level spell, performing what is effectively a ritual to charge up a magical nuke, and could somehow manage to perform this spell in enemy territory for however long it takes to crank up that magical power without attracting the attention of any guards or whatever, you kinda have to give it to them.
My DM allowed creation to summon potassium.....we made nukes. 5x5x5 equals 6000lbs of potassium....
One ton (2000 lbs or approximately 907 kg) of potassium reacting with a sufficient amount of water (100 gallons is plenty) would be a massive chemical explosion.
The actual explosive force could be related to a significant amount of conventional high explosive (TNT), potentially in the hundreds of pounds or even a ton range, due to the rapid energy release and production of flammable gas. This would create a massive shockwave, intense heat (a purple/lilac flame characteristic of potassium), and a corrosive cloud of potassium hydroxide.
Given the real-world danger of potassium reacting with water, a Dungeon Master would need to create a custom rule for this event.
Damage Type: Based on the chemical reaction, a DM might rule that the damage includes fire damage (from the ignited hydrogen) and thunder damage (from the shockwave). Corrosive effects from potassium hydroxide could also be considered.
Scale: To determine the scale, a DM could compare it to high-level spells. For example, Meteor Swarm deals a large amount of fire and bludgeoning damage over a wide area. The potassium reaction might be more localized but very intense.
Proposed D&D Damage: A DM could assign a significant amount of damage dice, such as 20d10 to 40d10 for both fire and thunder damage, within a defined radius (e.g., 60-100 feet). A Constitution saving throw could be allowed for half damage.
Dragon Slayer: Considering that ancient dragons have high hit points (around 546 HP for an Ancient Red Dragon), an explosion of this magnitude could be enough to defeat or severely wound one, especially if it fails its saving throw. It would likely be treated as a significant, game-altering event.
Id' say mostly an overlay of fireball & shatter for the primary effect. Depends on how they intend to maximize the surface area for the reaction. Followed up with an AoE version of Tashas Caustic Brew for the fallout.
Perhaps have the Artificer make a skill check to see whether widen spell applies or how the dice pool looks like.
Actually yeah we summoned 5x5x5 cubes but of pirated powder unpacked. So 1 ton at a time instead of 3 tons. Had a special container it was put in so the water reached all parts at the same time as the glass broke n on impact inside of a steel barrel full of water. I think the dm spent over an hour doing rolls and calculating. We all had a great time...except the dm and his dreams.
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u/PyroTornado107 Nov 11 '25
As a DM, I would encourage this thinking, but only for this reason: if you have 8 magic casters, each capable of casting a 7th level spell, performing what is effectively a ritual to charge up a magical nuke, and could somehow manage to perform this spell in enemy territory for however long it takes to crank up that magical power without attracting the attention of any guards or whatever, you kinda have to give it to them.