How forceful is Thaumaturgy's door slam?

[Ortho]

I'm asking this because last session, my players used Thaumaturgy to open a 90,000 ton door underground and I'm fairly certain that would have caused an earthquake of some kind. So currently I'm stuck trying to figure out the magnitude of both the earthquake and the damage done.

[Master O'Laughs]

I'm asking this because last session, my players used Thaumaturgy to open a 90,000 ton door underground and I'm fairly certain that would have caused an earthquake of some kind. So currently I'm stuck trying to figure out the magnitude of both the earthquake and the damage done.

I would think that lies outside the realm of a cantrip. I would think the ability of the cantrip is referring to your average run of the mill door, not something of that weight/size

[HappyDaze]

Think of a petulant teenager having a tantrum. The door is slammed about that hard.

[Ortho]

I would think that lies outside the realm of a cantrip. I would think the ability of the cantrip is referring to your average run of the mill door, not something of that weight/size

You'd think so, but Thaumaturgy doesn't mention anything about an upper limit.

[prabe]

You'd think so, but Thaumaturgy doesn't mention anything about an upper limit.

Sure, but I think you as DM would have been entirely within your rights to make it less potent than Telekinesis. This might be an instance of the decision to write 5E in something like natural language makes for problems when you have people used to rules-lawyering.

[Keravath]

I would think that lies outside the realm of a cantrip. I would think the ability of the cantrip is referring to your average run of the mill door, not something of that weight/size

It's a DM call. RAW the cantrip says it opens any door that isn't locked.

"You instantaneously cause an unlocked door or window to fly open or slam shut."

That doesn't put any limits on the size of door involved.

On the other hand the cantrip also says ..

"You manifest a minor wonder, a sign of supernatural power, within range."

So, opening a 90,000 ton (180 million pounds? Heavy door!), might count as a major wonder though it would certainly be a sign of supernatural power :).

The door could also be so well balanced, and magically enhanced with reduced inertia and frictionless hinges that it doesn't need as much force to open as one might expect. (Which would be required if you expect anything to be able to budge a door weighing in at 180 million pounds.

[KorvinStarmast]

I'm asking this because last session, my players used Thaumaturgy to open a 90,000 ton door underground and I'm fairly certain that would have caused an earthquake of some kind. So currently I'm stuck trying to figure out the magnitude of both the earthquake and the damage done.
I suggest a simpler approach.


How to Play

1. The DM describes the environment.
2. The players describe what they want to do.
3. The DM narrates the results of the adventurers’ actions.

I think you are making this too hard on yourself. (The other posts have some neat ideas and points, though)

[Chad.e.clark]

Was the door supposed to be immovable? If so, hey, it was magically locked, no opening super-door for you. Plot proceeds on as planned.

If you decide it was not magically locked, then hey, player made a clever move and plot changes based on a player playing their character cleverly.

[Ortho]

Sure, but I think you as DM would have been entirely within your rights to make it less potent than Telekinesis. This might be an instance of the decision to write 5E in something like natural language makes for problems when you have people used to rules-lawyering.

Yeah, I probably should've. I didn't, though. Because frankly, moving 90,000 tons with a cantrip is kinda crazy and I wanted to see how far down the rabbit hole this went.



The door could also be so well balanced, and magically enhanced with reduced inertia and frictionless hinges that it doesn't need as much force to open as one might expect. (Which would be required if you expect anything to be able to budge a door weighing in at 180 million pounds.

See, that weight came about as a result of me not bothering to calculate the density of steel before I made a giant whopping door out of the stuff. It was only after my players slammed it into the ceiling that we decided we should probably figure that out. (For what it's worth, I also described it as opening upwards - before I realized the weight of the thing, of course.)


I suggest a simpler approach.


How to Play

1. The DM describes the environment.
2. The players describe what they want to do.
3. The DM narrates the results of the adventurers’ actions.
I think you are making this too hard on yourself. (The other posts have some neat ideas and points, though)

Oh, I've already decided what the consequences are. Since I've already decided and explained to them that this caused an earthquake of some kind, and since they had the great misfortune to try this underneath a city built directly on coastal sand, so depending on the strength of the earthquake there's a non-zero chance they've liquefied the entire city (https://en.wikipedia.org/wiki/Soil_liquefaction). Which, by the way, I'm totally fine with. I'm not looking for damage control or anything of the sort; I'm honestly really impressed with the scale of destruction they've caused. (Though I'm in a shared campaign, so the tricky part will be running something this major past the other DMs....)

My end goal here is to figure out is exactly how large of an earthquake results from 90,000 tons of steel being slammed into the ceiling of an underground vault.

[Telok]

Do a quick google for the amount of force required to close a door and adjust the values for size, mass, and speed. Can't give more detail since at work.

Sometimes things are too awesome for rules whining. When someone starts flipping the lid of a 60' wide trapdoor spider hole with a cantrip you don't need to worry about weight, you need to roll a scatter die to see where the gnome lands.