The past decade has witnessed the burgeoning and continuous development of blockchain and its applications. Besides various cryptocurrencies, an industry that has quickly embraced this trend is gaming. Thanks to the support of blockchain, games have started to incorporate non-fungible tokens (NFTs) that can enable a new gaming model, play-to-earn (P2E), which incentivizes users to participate and play. While recent studies looked at several NFT games qualitatively and individually, an in-depth understanding is still missing, particularly on how the P2E model has transformed traditional games. In this work, we set to conduct a measurement study of NFT games, aiming to gain a comprehensive understanding of the effectiveness of P2E in practice. For this purpose, we collect and analyze relevant NFT transaction data from the underlying blockchain (e.g., Ethereum) of 12 games, supplemented with various data scraped from their websites. Our study shows that (1) a few top wallets control unproportionally high percentage of NFTs, and the majority of wallets own only one or two NFTs and do not actively trade; (2) promotion events do boost the trade amount and the NFT price for some games, but their effect does not sustain; and (3) few players actually earned a profit, and players in 9 out of 12 games who traded NFTs have a negative profit on average. Motivated by these findings, we further investigate effective incentive mechanisms based on game theory to improve the trading profits that players can earn from these NFT games. Both modeling and simulation results confirm the effectiveness of the proposed incentive mechanism.

翻译：过去十年见证了区块链及其应用的蓬勃发展与持续演进。除了各类加密货币，游戏行业也迅速接纳了这一趋势。得益于区块链技术的支持，游戏开始融入非同质化代币（NFT），从而催生出一种全新的游戏模式——边玩边赚（P2E），该模式通过经济激励吸引用户参与游玩。尽管近期研究对若干NFT游戏进行了定性个案分析，但学界仍缺乏对其深层机制的全面理解，尤其关于P2E模式如何变革传统游戏生态。本研究通过开展NFT游戏的实证测量，旨在系统探究P2E模式在实际运行中的有效性。为此，我们收集并分析了来自12款游戏底层区块链（如以太坊）的NFT交易数据，并辅以从游戏官网爬取的多维度数据。研究发现：（1）少数头部钱包地址掌控着不成比例的高额NFT资产，绝大多数钱包仅持有一至两个NFT且交易活跃度低；（2）营销活动虽能短期提升部分游戏的交易量与NFT价格，但效应难以持续；（3）实际实现盈利的玩家占比极低，在12款游戏中，有9款游戏的NFT交易者平均收益为负值。基于这些发现，我们进一步运用博弈论方法探究了提升玩家交易收益的有效激励机制。建模与仿真结果共同验证了所提激励机制的有效性。