Encyclopedia Magica: Al-Azid's Ghostly Palace

I love this type of magic item. In the spirit of Daern's Instant Fortress, Leomund's Secure Shelter, and Mordenkainen's Magnificent Mansion, the party is able to carry instant comfy camping wherever they go. The ghostly palace, though, comes with an Arabian flavor, and a nasty twist.

AL-AZID'S GHOSTLY PALACE



This huge palace of fine white marble and slender minarets is magically linked to the Ethereal Plane. It can be called into existence from that plane by the owner of the magical key to the palace's front gate. The owner of the key can summon the ghostly palace whenever needed, though it is only visible at night, when its walls shine in the darkness. By day the palace is invisible from the outside, though once inside, visitors can see its features easily.
The chambers within are well appointed, and gentle fountains play. Invisible musicians strum soothing tunes, and unseen servants take care of whatever cleaning, cooking, and menial chores the owner demands with a clap of the hands.
Al-Azid's ghostly palace is also subject to a curse, cast by Al-Azid to prevent others from enjoying his mansion after his death. Whoever bears the key that opens its doors is perpetually haunted by an invisible stalker.

One thing I find fascinating is that this item has almost nothing in terms of mechanics. No indication of how big the palace is, if it can be summoned inside or underground, how often it can be summoned, or anything. I find it oddly refreshing. Especially because, ninety percent of the time, such mechanics would either be irrelevant or obvious.

The super-cool part, and the area where I would like to see more details, is the curse. When it says "perpetually haunted", does that mean that killing an invisible stalker just summons another one? That certainly makes owning the key a trial. Presumably, any PC who owns the key would find some clever method to keep the stalker at bay. I mean, it's a summoned creature, so keeping up protection from evil would work.

It does open up one really interesting wrinkle, though. The key could work as an evil assassination tool. Give it to your target as a gift, then sit back and wait for the invisible stalker to do its job. Slip in and take the key back, then send it as a gift to the next sucker. (Or just let it get inherited, if you're looking to take out a family.) You would have to figure out some way to protect yourself while you had the key. My players would likely work to find some loophole in the definition of "owner".

As another nifty plot point, suppose the palace is currently owned by an NPC. The MacGuffin for the plot is currently kept by the NPC inside the palace. The party needs to either convince the NPC to let them in, or steal the key and get in themselves. Of course, once they steal the key, then they have to deal with the invisible stalker. Now that's an unexpected security measure!