The game was first published by Avalon Hill in 1985 as a successor to the award-winning "Squad Leader" series, on which the game is based and from which the rules and components were directly developed. By the time the fourth and final installment of "Squad Leader" debuted, there were four separate rulebooks in existence with poorly integrated and sometimes contradictory rules. For example, U.S. forces had lower morale and were therefore disadvantaged by the use of morale ratings to determine the ability to push ordnance through snow or mud, even though there is no real reason for morale to affect such an attempt. It was clear that the system had grown in ways never dreamed of in 1977; large amounts of "nutmail" to Avalon Hill convinced the developers of the need to streamline the rules.