The primary currency in STWALT is gold coins.
Gold coins are used for trade and services in the realm. You can earn gold coins by:
1. Working at the farm (there are 2 of them randomly placed in the map)
2. Stumbling across hidden gold stashes.
3. Opening a treasure chest with a key, or bashing or even picklocking.
4. Killing monsters in side quests or exploration. Powerful monsters have gold as loot.
5. Selling unused items, gear, weapons, armor to the castle or at a wandering merchant.
6. Once you have gold you can gamble at the tavern to increase what you already have.
7. Robbing strangers, merchants or a lone princess.
8. Begging for money at the castle.