From the back of the book:
The book of Mars is an effective combat system supplement to all role-playing games currently available. The information contained
within is an integrated, easy contolled blend of factual data and event probability of which some, any or all may be applied to enhance the realism of any game.
The book of Mars is an extensive reference source of military technology and combat technique ranging from the archaic past to near future. In itself, The book of Mars may be applied as basic rules for miniature wargaming capable of recreating any small scale infantry scenario whether historical or hypothetical.