Electronic game, device or computer program that provides entertainment by challenging a person's eye-hand coordination or mental abilities. Made possible by the development of the microprocessor, electronic games are marketed in various formats, such as hand-held one-player models, cartridges or compact discs that are inserted in modules attached to television sets, computer programs run on personal, tablet, or network computers or on smart phones, and freestanding arcade versions. Most of their appeal comes from the computer program that synchronizes flashing lights and a variety of sounds with the movielike animated action portrayed on a graphic display (see computer graphics). As the technology has advanced from 8-bit microprocessors to ever faster chips with greater graphic and sound capabilities, the programming has kept pace. For example, the newest games have so many levels and twists that they may take more than 100 hours to complete, and the graphic capabilities allow the game player to alter the visual perspective from narrow to panoramic. The games may be contested among several players, or an individual may engage in a test of skill against the computer. Some Internet-based games, known as massively multiplayer on-line games (MMOGs), involve thousands of individuals interacting with each other in ongoing, open-ended play. In MMOGs and other games, some businesses and individuals earn income through transactions involving virtual products that are used in the game, with such sales forming the bulk of the revenue of a number of game software companies. Game subjects include sports (e.g., baseball and football); action warfare, adventure, and role-playing; casino gambling (e.g., as roulette, poker, and simulated slot machines); and such classics as solitaire, contract bridge, chess, and backgammon.