Groats

Groats, from a Gopher Reward Token, take the form of paper scrip handed out to volunteers to thank them for shifts worked at the convention. Useable at the bar or hotel restaurant, and sometimes to buy t-shirts, they are more a novelty than a cash substitute. Often done in pretty patterns, and easy to overlook in a pocket, many a con treasurer is delighted when they are not all redeemed by the end of the con.

The volunteer nature of conventions means everyone works for pleasure, there are no employment or minimum wage issues that might occur in other professionally run events.

Article on UK usage