Are there any examples of chests hidden by the Leomund's Secret Chest spell being found?

Question

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.

Answer 1

[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:

This coven frequently leaves its den to roam the Ethereal Plane in search of treasure chests tucked away using the Leomund’s secret chest spell

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:

Kolstaag hides his valuables with the aid of a Leomund’s secret chest spell. He keeps the tiny replica needed to recall the chest on his person, or on a nearby nightstand while he sleeps. Only Kolstaag can use the replica to recall the chest, which he does before entering combat to gain access to the magic items within. If he’s captured, he can be persuaded to recall the chest in exchange for a promise of freedom. The extradimensional chest contains six 500 gp gems, Kolstaag’s bracers of defense, and a +1 wand of the war mage. -Chapter 2, Area T15

Hidden in the bed’s headboard is a secret compartment that can be found with a DC 15 Wisdom (Perception) check. It contains a small, bejeweled chest made of gold with platinum filigree. This chest is a miniature replica of a much larger chest that Sansuri uses as the main component of a Leomund’s secret chest spell. By touching the replica, Sansuri can recall the larger chest (see “Treasure”), causing it to appear within 5 feet of her. No other creature can summon the full-sized chest in this manner, which means the characters must persuade Sansuri to summon it for them if they want to obtain its contents (see “Development”). -Chapter 9, Area 33

The Wild Beyond the Witchlight:

Any character who searches the wagon for secret compartments finds one with a successful DC 15 Intelligence (Investigation) check. The compartment is located in a bench and contains a tiny, bejeweled chest worth 50 gp. This chest is a replica of a much larger chest hidden on the Ethereal Plane (with the help of a Leomund’s secret chest spell). While holding the replica chest, Mister Witch can use an action to summon the larger chest. He can send the larger chest back to the Ethereal Plane by using an action and touching both the chest and the replica. -Chapter 1, "Staff Area"

Waterdeep: Dungeon of the Mad Mage:

Treasure. Spite keeps a tiny jeweled chest inside his rolltop desk. This chest (50 gp) is a replica of a full-sized chest made of exquisite materials. The larger chest (5,000 gp) is hidden on the Ethereal Plane by means of a Leomund’s secret chest spell.

A character can recognize the miniature chest for what it is with a successful DC 15 Intelligence (Arcana) check. Spite alone can use the replica to recall the larger chest, which contains two spellbooks titled Spells of Spite, volumes I and II. -Level 9, Area 11a

Out of the Abyss:

The drawers of the desk are sealed with arcane lock spells. Picking a drawer’s lock requires thieves’ tools and a successful DC 23 Dexterity check. A knock spell or a successful dispel magic (DC 15) cast on a drawer removes its magical lock. When opened, the drawers are empty. An effect similar to Leomund’s secret chest shifts the drawers’ contents into an extradimensional space when anyone other than Gromph opens them. -Chapter 15, "Gromph's Outer Sanctum"

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.

Answer 2

In 5e, what does the spell do?

You hide a chest, and all its contents, on the Ethereal Plane...While the chest remains on the Ethereal Plane, you can use an action and touch the replica to recall the chest...If the spell ends and the larger chest is on the Ethereal Plane, it is irretrievably lost.

We know that one of the spell effects is that it "hides" the chest - so what does it mean to be hidden? In 5e, can hidden things be found?

Well, yes, if they are game-term Hidden. To find something game-term Hidden, you just need a Perception (roll or passive score) better than the Stealth (roll or DC) of the thing that is Hidden. But the spell doesn't seem like it is using Hidden in this sense, so it is likely using hidden in the plain English sense. In natural English, can hidden things be found? Why, yes again - so it might be possible to find chests that were hidden by the spell.

In natural English it is not clear, however, whether the action of the spell hides the chest as a 'one and done' event ('I hid the cookies in the cupboard'), or continually hides the chest throughout the duration of the spell ('The clouds hid the moon all night'). If the chest is hidden the first way, it most certainly could be found, but if it is hidden the second way, it might not be possible to find it without somehow ending or overcoming the spell.

The spell does not only hide the chest, though - it also can be used to recall the chest from its hiding place. This is important because if the chest is still hidden when the spell ends, it is "irretrievably lost". In natural English, something that is irretrievably lost can't be retrieved, but might still be found. It is a spell effect that recalls the chest from the Ethereal, and once the spell ends, it can no longer do that, but this doesn't preclude other means of recovering the chest. As a linguistic analogy, suppose the chest is a lure and the spell is a fishing line. When I go deep sea fishing, every time I cast, I can retrieve my lure. But if my line breaks, my lure is irretrievably lost, because I can no longer retrieve it. It is not completely lost, though, as I could go diving and attempt to find the lost lure on the sea floor. It is lost, but it could be found.

So, my best RAW analysis says that chests that were hidden by the spell can be found on the Ethereal, but they are no longer accessible from the Prime - you would need to go the Ethereal itself and look for them - much as the hags from Icewind Dale do, as Thomas Markov's answer relates. It remains unclear whether the chests there were just hidden once or are 'actively' hidden while the spell is still running; that is, it is unclear whether or not the only chests that can be found are those on which the spell has ended.

In previous editions, the chest could be found while hidden

From the First Edition Leomund's Secret Chest spell description:

While on the ethereal plane, there is a 1% cumulative chance per week that some creature/being will find the chest. If this occurs there is 10% likelihood that the chest will be ignored, 10% possibility that something will be added to the contents, 30% possibility that the contents will be exchanged for something else, 30% chance that something will be stolen from it, and 20% probability that it will be emptied.

Thus, a chance that the chest could be found even while the spell was running was part of the spell description itself in first edition.

What I would do

5e is a kinder, gentler playing experience than 1e was (I was there). Having players' chests found and taken while under an active spell, when that is not explicitly part of the 5e spell description, would be regarded as a 'jerk DM' move by most current players. Drawing on 1e lore and having this happen to NPCs in a 5e game, however, might be an effective a plot hook when one of them then hires the PCs to get their stuff back.

Should the players have this spell, a very effective villain could be made from an antagonist 'who has figured out how to find actively hidden chests' and is looting their contents. The players might have to thwart such a reprobate while taking extra precautions with their own things. Such a turn in the campaign would need to be clearly telegraphed first though, with the PCs hearing of this horror befalling other unlucky wizards long before it happened to them.