From the introduction:Retro is a tactical World War II infantry combat variant rules set. Gamers may utilize these rules and the components of Avalon Hill's Squad Leader, Advanced Squad Leader, or other popular tactical wargames to recreate World War II battles in a simplified, playable format. Though Retro enables you to make use of Squad Leader and ASL components and modules, it is not endorsed nor authorized by Avalon Hill or other publishers. Retro should be viewed as an unoffical variant to these fine games, and presumes that players own official modules and rules.Originally appeared in issues #1-#4 of Panzerschreck magazine, published here as a 48-page booklet with two pull-out charts.Signficantly strips down the sequence of play, armor rules, and morale rules of ASL. A significant innovation is the concept of 'hesitation' (which replaces most of ASL's defensive fire rules), where units moving in the open and in range of the enemy must test to determine if they freeze in place and don't carry out their move.Designed with solitaire players in mind, or anyone wanting to play these classic tactical wargames with less rules overhead.Retro's page at Minden: http://www.homestead.com/minden_games/Retro.htmlExpands: Advanced Squad Leader Squad Leader - BoardGameGeek