Abstract: A tool is provided for designing electronic games of chance such as slot or fruit machine games. Software that runs on a computer or remote server takes user inputs and selections such as game rules, input data, and pointers to or import of files (such as sound and graphics files). The output data of such a tool may be a file or parameters that specify one or more of hit rate, return to player, pay-table, symbol mapping, symbols, game theme, risk profile, rules of game play, denomination, language, currency, display, simulation results, pay methods, triggers for game features or jackpots.