Virtual Economy
Virtual Economies are systems that enable users to control virtual currency and virtual items within a virtual world or other metaverse experience.
Many free-to-play games have economies that allow players to earn some items and pay with actual money for others.
Economies may be characterized as:
Closed (e.g., as one finds in World of Warcraft or Fortnite). If there are third-party marketplaces for exchanging items or currency in these games, it is usually prohibited by the world’s terms of service.
Open and centralized (such as usually found in a game like Minecraft), where participants can contribute to a creator economy within certain constraints.
Open and decentralized (such as found in some blockchain games such as Decentraland or play-to-earn games). In contrast to closed economies, these games are typically compatible with decentralized marketplaces that allow players to exchange items and currency with each other—and their systems are designed with this openness in mind
Further Reading
How Virtual Worlds Work, series by Raph Koster, leading innovators of MMOs.