Jarindr Thitadilaka said he made as much as US$2,000 a month last year from his collection of digital pets, which he would breed and send into battle to win cryptocurrency. The 28-year-old from Bangkok was playing Axie Infinity, one of a new breed of blockchain-based online games dubbed “play-to-earn,” which blend entertainment with financial speculation. These games can make for lucrative businesses amid the hype around non-fungible tokens (NFTs) and virtual worlds, attracting millions of players plus billions of dollars from investors who see the games as a way to introduce more people to cryptocurrency. Photo: Bloomberg In Axie Infinity,...