Video games can include elements that use blockchain technologies, including cryptocurrencies and non-fungible tokens (NFTs), often as a form of monetization. These elements typically allow players to trade in-game items for cryptocurrency, or represent in-game items with NFTs. A subset of these games are also known as play-to-earn games because they include systems that allow players to earn cryptocurrency through gameplay. Blockchain games have existed since 2017, gaining wider attention from the video game industry in 2021. Several AAA publishers have expressed intent to include this technology in the future. Players, developers, and game companies have criticized the use of blockchain technology in video games for being exploitative, environmentally unsustainable, and unnecessary.