The need for travelling money has always been with us. From the copper lumps that the Iceman of Austria/Italy carried almost 5000 years ago to the coils of silver and gold found in Viking treasure hordes (snipped of sections as they went) to the rings and jewelry of the middle ages there has been a need for portable wealth. Currently in the USA there are families of Vietnamese immigrants who still keep large amounts of gold in the family home. Just in case they need to pack up and move quickly. Nothing like 20 oz of bullion to get you passage out of a bad situation.
So gold, (or lanthanum, or Uranium chips, or silicon chips, or TL12 antibiotics) will still have a place in the Traveller universe. As stated here, earlier in the topic, on high tech worlds, with stable economies, there are electronic asset transfer systems in place to handle paychecks and groceries. Ships would likely have letters of credit, drawn on Hortalez et Cie or Instellarms or any other sector or Imperium wide agency. (Adventure Idea: Characters come across a Navy Bearer Bond worth many many credits, but they can only redeem it at the nearest Depot due to its age. They have to protect it and carry it across the parsecs, adventures along the way. Humorous Irony being that they have this great wealth but their actual cash is so low they have to work odd jobs just to collect the monies.)
Part of the fun and little details that could make a game great would be making the characters look up in the library data what the most popular item of exchange on the next planet in would be. This could sort of be like the Trader or Broker skill where the future value of the cargo can be somewhat predicted, but it would be a more stable commodity. Like "Onesium is a low tech world and gold, silver and jewels do well. Twosium is a high tech world with iron poor soil so iron coins are popular. Threesium is a desert world so bring water. Foursium has an early TL 7 technology so bring Zero G manufactured Silicon Chips set to IMPNAVSPEC 12-b and you can get a hotel room and a meal for the night."
This is something the referee can make up randomly, base on the planet info, UWP, Tarot cards, what have you. IT would add color and be in keeping with being paid in "Credits"
Two forms of credit or actual cash money that would be popular in the Imperium: MegaCorp Chits, useable in any nearby MegaCorp chain store at full listed face value; IISS Mail vouchers, good for sending mail any where in the Imperium at posted rates. People would be able to use those as a standard against which to buy and sell goods. Indeed the IISS mail vouchers might just BE Imperial Credits. It is one of the only universal standards within Traveller that is consistent and Imperium wide. It even extends into the extra-Imperial regions. Since X-Boats are the most reliable form of business communications, they would be sought out everywhere. The Imperium could even have the job of printing Credits assigned to the IISS. There is a job for your Detached Duty scouts! "You have been reactivated to take this shipment of Credits to BFE. By the way every con artist and corsair in the surrounding 3 subsectors has somehow found out about this shipment. Good Luck!" Hilarity ensues.
