Based on the famous Bag of Holding, this mundane looking coinpurse has similar properties. Upon inspection, it functions as a normal coinpurse, holding up to several dozen coins. Opening it allows you to deposit coins, or dump them out. It does not even radiate as a magic item. However, when the command word is spoken, it now radiates as magical, the opening instead leads to a much smaller version of the bag of holding, allowing up to 2 cubic feet of materials or a max weight of 20 pounds, to be placed inside. The opening can be stretched to accommodate items up to two feet in circumference. The coinpurse only weighs 1-2 pounds, depending on how many coins are placed inside as a normal item.
If the bag is overloaded, pierced, or torn, it ruptures and is destroyed, and its contents are scattered in the Astral Plane. If the bag is turned inside out while activated, its contents spill forth, unharmed, but the bag must be put right before it can be used again.Because this item is meant only to store inanimate objects, any living creature placed inside will immediately begin to suffer from suffocation, until they die. Any living creature placed inside cannot exceed the size and weight limitations of the coinpurse.
Placing a coinpurse of contraband inside an extradimensional space created by a bag of holding, handy haversack, portable hole, or similar item instantly destroys both items and opens a gate to the Astral Plane. The gate originates where the one item was placed inside the other. Any creature within 10 feet of the gate is sucked through it to a random location on the Astral Plane. The gate then closes. The gate is one-way only and can’t be reopened.
Notes: The owner can set the command word to function as an extradimensional container when they attune it to themselves. Embossed into the leather on the coinpurse is the outline of a hare's head, with a unicorn's horn protruding from it. A successful Investigation or Religion roll (DC 14) will reveal that this is associated with one of the nine trickster gods of Chult, I'jin. , Utility, Container
I came up with this idea before we ever had a rogue in the player group. A bag of holding seems very generic, you can practically buy one on every corner in Neverwinter. I thought, why not something far more uncommon, flavored for a rogue?
Oh and it ceases to radiate magic after you close the extradimensional space. I introduced this by telling our rogue that a near miss by an arrow shot at him, instead hit his coinpurse, and spilled all his coins onto the floor. While searching bodies after the battle, I informed him that he seems to have found a suitable replacement, a nicely crafted and embossed coinpurse.