In spite of LadyGoo's idea to eliminate the altvaulting.
It's setting the balance a bit to the other side.
With charter stones and altvaults attacker gets nothing. Without them defender can keep nothing. Both are bad.
I'd think about some fair way to make a fair way to keep some goods.
My idea
Make a strongbox. Unmovable. With soak of bwall or higher. With price around 2-5 steel bars. And with 'drying' feature of brickwalls (gradual soak gain).
Add a lockpick skill.
By default there is:
a) 25% chance to unlock successfully
b) 25% to fail without consequence
c) 25% to fail the lockipcking completely, while safebox owner still can open it with a passphrase. If unlocked - goes to initial state.
d) 25% to stall the lock completely so stuff is gone forever.
Raising of lockpicking skill shd raise the chance of A and lower B and C. Raising the strongbox q shd lower the chance of A and D and raise B and C.
I'd balance it so q90 box is evened by 250-300 lockpicking, q40 box is evened by 100 lockpicking (meaning that chances at these levels are the same as default ones)
Lockicpking shd be a bit time consuming (1 min - 5 min) and stamina hungry.
For the owner to unlock it the passphrase is probably the most correct way since keys will be available to steal from characters.
So the defender can invest into trying to protect some stuff. But in the end he wont be able to keep everything we wanted while the attacker wont be able to get everything. And the Holy Random is involved
// discuss
PS
Updated to clarify the situation when items can only be retrieved by owner but not by anyone else.
PS2. Clarified that if safebox goes to state C (only unlock by passphare) and then is successfully unlocked by owner - it goes to initial state and can be lockpicked again.