From the introductory description: Modem is modeled after the matrix in Shadowrun. In this game the computer hacker sees the world around him as a computer system, not some simulated city or countryside. The characters log into the matrix through a Cyberdeck (which is a computer) that controls how they appear, how strong their attributes are, and what kind of programs they can use. Leveling in this game is how the characters earn money, which they in turn use to buy upgrades and become stronger. They can also earn money through missions (usually to steal information from Datastores). The matrix consists of computer systems, each with its own address. Usually at the beginning of a mission the character is given the address of a system to hack and the knowledge of what they're looking for. The GM constructs this system ahead of time plus the Artificial Intelligence (AI) programs that guard it. These computer systems consist of Nodes. Each Node connects to another and each has specific tasks. Most Nodes have a rating, which determines who hard it is to use or pass through them. They also have AI guarding them that the character will have to fool or battle. Failing to do these things can trigger alarms that alert the owners of these systems. Then things get harder as the employed hackers from those systems login to try and discover the cause of the alarm. This game actually does have a "happy ending" for the characters. Upon reaching level 10 the characters can retire. Game over, you win.