Whereas some games have been around since humanoids dragged their knuckles across the plains of Africa, others have only emerged since those knuckles have wrapped around cellphones. Imaginary money is one of them.
Standard (fiat) currencies such as pounds, dollars and rands are issued - and, importantly, backed - by central banks or governments. But they’re not the only way of paying for things.
Over the last couple of years, cryptocurrencies, also called digital currencies, have become increasingly accepted by people and merchants as a means of payment for goods or services. Bitcoin, Ripple, and Ethereum are probably the best known.