From the Introduction in the book: Tomorrow’s War is a science fiction military miniature wargame with emphasis on "hard" science fiction rather than "Space Opera" or "Science Fantasy." This rule book contains background material for gaming in Ambush Alley's campaign setting, the colony world Glory, but the rules themselves are not background dependent. You can use them to game gritty science fiction engagements against whatever narrative backdrop you choose. Tomorrow’s War can be played with figures of any scale, but the rules assume players are using 15mm figures. Version: 1.0.2, 13 September 2010 For use with 1st Edition Force on Force.