SSN is a simulation of modern tactical submarine/anti-submarine warfare set in 1970-1979. Players each direct 1 to 17 ships or submarines (with associated helicopters) over a plain hex map to recreate cold war naval doctrine.The players plot movement and missions for their units secretly before moving, attempting detection, evading and attacking simultaneously.Three peacetime and nine wartime scenarios are included. Vessels range from Soviet SS to US CVN types. British, Canadian and French units are also represented.All units are represented by 1/2' counters. The game scale is 1000 yards per hex and 6 minutes per turn. The combat system is based on an odds-based CRT with different effects for nuclear and conventional weapons systems. - BoardGameGeek