Magic item: Arcane Puzzle Box

[Mystify]

This was an item I added in a campaign a while ago, and I thought it worked well and was interesting. I'm sure a creative DM can come up with all sorts of uses for these.

Description:
You see a small box, about 6 inches on a side. It is covered in colored panels, arcane symbols, sliding panels, hinges, and small doors.

DC 20 knowledge (arcana) check to identify it as a puzzle box. This reveals the following information:

The puzzle boxes are an old wizard trick. Used to safeguard important items, these boxes contain a non-dimensional space, much like a bag of holding. Breaking the box open destroys the link, so the only way to access its contents is to solve the puzzle. These puzzles are not intended to be solved, and so are fiendishly difficult to crack without knowing the trick.

It requires 8 hours to attempt to open a puzzle box. At the end of this time, you make an intelligence check. Success means you have opened the box, failure means its solution has eluded you once again. The DC required varies from box to box, but are generally in the 25-30 range.

When the box is closed again, the box unsolves itself, and must be re-solved to open it. Once you have solved a particular box once, you can resolve it in half the time(4 hours) with a +5 on your intelligence check. Since each box has its own puzzles, solving one box does not give you any bonus on other boxes.

The size of the extradimensional space inside varies from box to box. Some contain as much space as a bag of holding, others are no larger than the box appears, and only serve to shield against breaking open the box. An opened box often unfolds, allowing enough space to easily access whatever item is contained within. Some spiteful wizards store poison or other traps inside the mundane box. When opened properly, the extradimensional space blocks access to the trap, but if broken open the trap is triggered.

Some wizards create decoy boxes, which only contain a trap or a dangerous creature who will attack those who open the box.

[Chronos]

A fun concept, but "I spend 8 hours and then roll an Int check" doesn't sound very fun. Also, a DC of 25 means that nobody has any chance of opening one without an artifically-boosted intelligence, but it seems like someone of high-normal Int should be able to at least have a chance.

[Mystify]

A fun concept, but "I spend 8 hours and then roll an Int check" doesn't sound very fun. Also, a DC of 25 means that nobody has any chance of opening one without an artifically-boosted intelligence, but it seems like someone of high-normal Int should be able to at least have a chance.

an 18 int person can crack it on a 19 with an aid. Remember, these are made by moderate level wizards, who do have artificially high ints, and they know how it works so they get the +5 to solve it. Hence, they could crack a DC 30 puzzle box.

Its meant to be a form of delayed gratification. We acquired a puzzle box, and the smart people in the party are sitting there trying to figure out how to open the stupid thing. It will either have a trap, or something really cool inside. You don't put spare change in a puzzle box.

[InfiniteNothing]

Okay, this is cool. I like it.

What are the requirements to make one of these things?

[Mystify]

Okay, this is cool. I like it.

What are the requirements to make one of these things?

I would do it in 3 parts, design, consturction, and enchantment.

First, you must design the puzzle. You do this by spending 8 hours and making an intelligence check, just as if you were solving it. If the DC is not to your liking, you can retry. you can also set the DC lower than what you roll.

Then the puzzle box itself. Its would be a craft check, DC 20, of a relevant skill(mechanical device, locksmith, something like that). Cost 200gp.

Next step is to enchant the box. Since its using the extradimensional space, you need the secret chest spell, just like making a bag of holding. The price would depend on the size of the space inside; I would use the handy haversack/bag of holding as a price point for the relevant size, depending on what you want to store.

The puzzle box is mostly mundane, it just uses the extradimensional pocket to protect against smashing it open.

[Grod_The_Giant]

The puzzle box is mostly mundane, it just uses the extradimensional pocket to protect against smashing it open.

Does that mean I could use disable device/open lock to futz with the mechanism until it opens?

[Mystify]

Does that mean I could use disable device/open lock to futz with the mechanism until it opens?

Its not a lock, but disable device may work. However, it would be a high DC. I based the mundane specifications off of an amazing DC 40 lock, and boosted it a bit higher, so I would expect the disable device DC to be at least that high.
Additionally, the extradimensional space is linked to the puzzle, so forcing it open like that would just expose you to the trap, not open the extradimensional pocket. That probably wouldn't render the puzzle unsolveable, unlike smashing it, but it wouldn't yield the desired results either.