Banking and Economics
( ⇪ Lore )
Hyperion planets have access to “The Bank”. The Bank has a withdrawal limit equal to the community’s “gp Limit” (DMG page 137) for any given day. However, you can deposit as much raw cash (in gp, sp, and cp) as you want (other loot must be converted to cash before being deposited). You can also make transfers to another account at The Bank, but special restrictions may apply (at the GM’s discretion) such as transfers being limited to only being able to transfer so much each day. You can spend any amount of your banked money at any establishment that accepts The Bank, although those generally also accept raw cash.
If you’re not on a Hyperion planet, to determine the amount of ready cash in a community, or the total value of any given item of equipment for sale at any given time, multiply half the gp limit by 1/10 of the community’s population. For example, suppose a band of adventurers brings a bagful of loot (one hundred gems, each worth 50 gp) into a hamlet of 90 people. Half the hamlet’s gp limit times 1/10 its population equals 450 (100÷2=50; 90÷10=9; 50×9=450). Therefore, the PCs can only convert nine of their recently acquired gems to coins on the spot before exhausting the local cash reserves. The coins will not be all bright, shiny gold pieces. They should include a large number of battered and well-worn silver pieces and copper pieces as well, especially in a small or poor community. If those same adventurers hope to buy longswords (price 15 gp each) for their mercenary hirelings, they’ll discover that the hamlet can offer only 30 such swords for sale, because the same 450 gp limit applies whether you’re buying or selling in a given community.
There’s official justification for the worth of a Gold Piece. The primer statement about hand-waiving the trappings of a setting applies: We don’t need to dig into economic theory any more than the Dungeon Master’s Guide except to say that The Bank carefully crafted a set of wish spells such that they are the sole possessors of the secret true creation rituals for “commodity money” (pp, gp, sp, cp) and their own same-named “fiat money”, as well as for directly transforming money between the “commodity” and “fiat” forms.