Changyou.com Ltd was incorporated on August 6, 2007 in the Cayman Islands. The Company develops, licenses and operates new MMOGs and Web and mobile games. It also owns and operates the 17173.com website, an information portal for gamers in China. The Company operates its current games under the item-based revenue model, meaning game players can play games for free, but may choose to buy prepaid game cards that are used to pay for virtual items, which are non-physical items that game players can purchase and use within a game, such as gems, pets, fashion items, magic medicine, riding animals, hierograms, skill books and fireworks, to enhance the game-playing experience. It sells its prepaid game cards to regional distributors and its game players in China through its online sales platform, who in turn sub-distribute them to numerous retail outlets, including Internet cafes and various websites, newsstands, software stores, book stores and retail stores. The Company currently operates 11 MMOGs, three Web games, and several mobile games. The key games that are currently in operation include TLBB; DDTank; Wartune; the Blade Online series, which consists of BO and BH2; DMD; DHSH; Dou Po Cang Qiong; Wartune "mobile version" and TLBB "mobile version". TLBB is an in-house developed 3D martial arts MMORPG adapted from the popular Chinese novel, "Tian Long Ba Bu," which means "Novel of Eight Demigods. DDTank is a popular 2D multi-player, combat and role-playing Web game in China. Game players control avatars to compete with other game players. Wartune is a popular 2.5D role-playing and quasi real-time strategy Web game in China. Wartune is set in a mythical western universe where players build their own kingdoms in a virtual world where they must fight against a demonic race by developing their own villages and armies. It relies on trademark and copyright law and trade secret protection, and intends to rely on PRC patent law if its currently pending PRC patent applications are approved, to protect its intellectual property rights. The Company competes with other game information portals, such as duowan.com, operated by YY Inc., and game.qq.com, operated by Tencent Holdings Ltd., and other Internet portals which have, or may over time be able to build, competitive advantages over the company in terms of greater brand recognition among game players and advertising clients; larger user and customer bases; more extensive and well developed marketing and sales networks; and substantially greater financial and technical resources.