Spoils key
A plain iron key on a tally tag with a name cut into it. The Tally House on Muster Square in Thornwall holds what the name dropped, and opens the strongbox for this key alone.
How to get it
Kill a player on a dangerous world: they keep their three most valuable items and the rest goes into a chest at the Tally House in Thornwall. The key to it lands in your pack, cut with their name.
With your pack full, Tallyman Orrin holds the key for you instead. Ask him for it with one space free.
What it is for
Open the strongbox at the Tally House: take what the chest holds a row at a time, or all of it if your pack has room. The empty chest takes the key back.
The bank and the trade window refuse it. Dropping it destroys it, and the chest with it, after a warning. You keep it when you die.