In SLASH'EM, The Wallet of Perseus is an unaligned artifact whose base type is a bag of holding. It works like any other bag of holding, only better. With the given BUC status below, where x is the combined normal weight of all items in the Wallet, the Wallet's actual weight will be:
- Blessed (x + 5) / 6
- Uncursed (x + 2) / 3
- Cursed 4x
A blessed bag of holding uses the above formula, but divides its weight by 4 not 6, so The Wallet of Perseus can hold roughly 50% more than a regular bag of holding. For pack-rats (of the '@' kind, not the 'r' kind), this is an extremely useful artifact, though obviously not one which directly aids in survivability. For some characters (depending on play style and early game needs), it may even be worth spending a second or third wish to acquire.
The Wallet is destroyed by inserting a wand of cancellation or a bag of tricks, so being careless with either of those around it is a very bad idea. Unfortunately, when cursed, it quadruples the weight of items inside: it will very likely be too heavy to lift. Therefore, you should always have a wand of cancellation around to uncurse it.
It is certainly a must-have for every self-respecting thief. Consider: After a successful assault, you can strip Fort Ludios down to its brick-n-mortar of all its items and loot, including the landmines, in about 3 trips. Or you can abscond with ol' One-Eyed Sam's marginally useful loot all in one shot without even being encumbered. And in the early to mid game, you can usually move your home base including all your valuables in just one trip. No Rogue, at least, ever leaves home without his Wallet.