The description of the spell Leomund's secret chest says:
You hide a chest, and all its contents, on the Ethereal Plane. […]
This question asks where the chest is hidden, with the single answer being that it's a matter of worldbuilding.
Are there any examples in rules or lore of chests hidden on the Ethereal Plane using the spell then being found?
I am first and foremost looking for official published 5e references, but any published material from previous editions would be interesting.
As both a player and a GM, I'd like to know of any such examples so that I can discuss the spell from an informed position.
Best Answer
[This answer is specific to 5th Edition material]
At best, we can show that searching the Ethereal Plane may yield results.
There are no examples of hidden chests that can actually be found on the Ethereal Plane; in the section below, I document all of the spell's uses in published adventures. However, there is some evidence that a "brute force" search of the Ethereal Plane might not be an entirely fruitless endeavor. In Icewind Dale: Rime of the Frostmaiden, we meet a coven of hags, and the module states:
The important takeaway here is that they wouldn't be doing this if chests were impossible to find. Obviously, the DM can work it into the adventure that the party stumbles across a secret chest on the Ethereal Plane, but it is nice to see an official reference that demonstrates such a thing might actually be feasible if you have a reliable method of planar travel.
There are five that can be accessed while the chests are not hidden away.
We've got five examples from published adventures, none of which are found on the Ethereal Plane.
Storm King's Thunder:
The Wild Beyond the Witchlight:
Waterdeep: Dungeon of the Mad Mage:
Out of the Abyss:
The recurring theme in all these examples is that only the owner may access the chests. There is no direct access method provided in any of the adventures, and the Ethereal Plane location is never given for any of these chests. In each case, accessing the contents of the chest will require either persuasion or coercion of the owner.