This free "Harpoon V: Jumpstart" explains the rules system to new players and familiarizes veteran Harpoon players with the many changes made to the fifth edition rules. The previous fourth edition was last updated in 2001(!), so there’s a lot of catching up to do, not only in terms of new systems that have appeared, but better ways of modeling the complex interactions and technical details of modern naval warfare. Seriously, there are a lot of moving parts. For example, a detection by radar is affected by the range of the contact, its signature (which is not the same as its size), the type of radar, the radar’s technology level, the weather, the contact’s proximity to land, and how quickly the detection is processed (a new feature in this edition, the combat system). And then there’s offensive jamming. Harpoon is a complex game. It is playable because we have worked hard to ruthlessly simplify the many interactions and abstract, or “black-box” processes that would otherwise slow manual play to a crawl. We want the game to be about making decisions, based on real-world trade-off s. This game requires that you learn about naval warfare. Like any game, the more you understand, the better your chance of winning. The rules explain, in real-world terms, how radar, sonar, and other sensors work. Some of it is arcane; all of it is real. And in naval warfare, finding the other side is the hard part.