Advanced Squad Leader, successful World War II tactical board wargame produced by Avalon Hill from the mid 1980s onwards. Units are individual vehicles and infantry squads/sections; reconfigurable hex-grid maps were on a scale of 40 m to the hex. A development of the (surprise!) Squad Leader game, it was designed in a modular fashion: you started with the Eastern Front module Cross of Iron and the (separately purchased) rulebook, and added maps, extra rules, and units from other armies and theatres of increasing levels of obscurity. Used as the basis for a number of computer games since.