The Internet has enabled the popular pastime of playing video games to grow rapidly by connecting game players in disparate locations. However, with popularity have come the two challenges of hosting a large number of users and detecting cheating among users. For reasons of control, security, and ease of development, the most popular system for hosting on-line games is the client server architecture. This is also the most expensive and least scalable architecture for the game publisher, which drives hosting costs upwards with the success of the game. In addition to the expense of hosting, as a particular game grows more competitive and popular, the incentive to cheat for that game grows as well. All popular online games suffer from cheats in one form or another, and this cheating adversely affects game popularity and growth. In this dissertation we follow a hypothetical game company (GameCorp) as it surmounts challenges involved in running an on-line game. We develop a characterization of gamer habits and game workloads from data sampled over a period of years, and show the benefits and drawbacks of multiplexing online applications together in a single large server farm. We develop and evaluate a geographic redirection service for the public server architecture to match clients with servers. We show how the public server game architecture can be used to scalably host large persistent games such as massively multiplayer (MMO) games that previously used the client server architecture. Finally we develop a taxonomy for client cheating in on-line games to focus research efforts, and specifically treat one of the categories in detail: information exposure in peer-to-peer games. The thesis of this dissertation is: a methodology for accurate usage modeling of server resources can improve workload management; public-server resources can be leveraged in new ways to serve multiplayer on-line games; and that information exposure in peer-to-peer on-line games is preventable or detectable with the adoption of cryptographic protocols.