Currency and trade
The battery wallet
Serendipity is a fairly new settlement and many people coming through usually trade with exchange of common or exotic goods - however the currency of the town is power. Many things can be bought, foraged or hunted for, but power to keep the protective shields up and running, not to mention heat, lights and various other necessities is a rare commodity. Every resident carry a battery wallet, which can be seen on the picture below. All players start with 5 clicks on their battery marked by luminescent ink derived from the mushrooms that grow around the settlement. The ink only checks out in a black light, which all establishments will have available.
The battery is simply plugged into the establishments' socket and the number of clicks due is withdrawn - or added. There are communal sockets made available for private trades on the marketplace.
Shdari - The Harmony Coin
However - the Harmony Collective are working on getting their own currency more popular amongst the settlers. Shdari is a small kind of coin made from the Éllalu crystal that makes them quite precious but also hardened and sturdy, standing tests of time and all kinds of weather. The locals call them 'harmony coins' as a sceptic little remark on the colonizing move of enforcing a currency to rural areas who already have functioning systems of economy. Many believe it an arrogant move, but the Collective stand by their only intentions of bringing the peoples closer together and breaching gaps of all kinds - currency included.
Some accept shdari, some don't - but every settled resident in Serendipity accepts clicks from a battery wallet. Everyone has generators to charge.