Well, you all know
the spell, and I consider using it for a wizard of mine in Paizos Rise of the Runelords campaign.
While I do not like the fact that the chest, containing my most valuable possessions, will just be laying around in the ethereal plane for anyone to tamper with, I remain confident that I can the chest can be secured quite well with a decent amount of optimization. The spell dictates that the hest must "be exceptionally well crafted and expensive, constructed for you by master crafters", and hat it may cost no less than 5000 GP for the spell to function. Non-optimizers will buy a gold adorned, gem encrusted blinged out piece of shit chest made from exotic and expensive wood, but I see the price as an invitation to make the chest virtually impenetrable.
In short, the purpose of this exercise is to make a 3x2x2 ft. chest as secure as possible, even when it is left unattended on the ethereal plane, for the price of 5000 GPs.
My initial thoughts:
1) Fitting the chest with two amazing locks will render it quite hard to open for most creatures in a standard D&D world, and it wont break the 5000 GP budget. One key will be carried by my character, and the other by my familiar.
2) A 3x2x2 box can potentially be very heavy, and if I can make it heavy enough I can perhaps deter most wizards and ethereal critters from picking it up and wander off with it (NetHack style :-P). Lead seems to be an optimal building material here, as it will double as a divination firewall, and I suppose that I can remedy the metals inherit softness by covering the chests surfaces with permanencied walls of force.
3) Fire Traps are virtually free, and while they wont actually do anything to creatures powerful enough to get to the chest in the first place, I might as well cover it in them... Just for fun.
4) If the chest is ever lost, I need a way of locating and/or retrieving it, no matter which plane it ends up on. I need a suggestion here though.
5) Non-living minions can be placed inside the chest, and attack any thieves or saboteurs who open it. My character is LN, so creating some intelligent undead to help protect the chest is not out of the question. Shadows in peculiar would be a nasty surprise for anyone, espicially casters, who are the most likely culprits to get to the chest in the first place. I just have to keep them out of sight of the party paladin.
6) My last idea is a little meta-gamey, but I hope to protect the chest with plot armor, by placing important plot-related objects inside it at any given chance.
Anything else that can be done to protect the chest?