Up Front is played by two players in rounds. Each player handles cards of Men, Armored Fighting Vehicles (AFV) and Infantry Guns (IG) that are set up in the table in units (groups A to D), according to the scenario and the nationality to be played. By playing action cards (the actual “machine” of the game) each player maneuvers his groups in a way that he will accomplish his goal, which is the “victory conditions” of each scenario. There is a “relative range” concept between opposing forces that influences respectively the play of action cards. Movement, Fire, Rally, Flank, are only some of the actions a group can make with his action cards. Different types of weapons are used and each man is initially assigned to a certain weapon. There is no playing board; it has been replaced by terrain cards. Terrain cards are actually action cards that are played by a player in front of his group to show where the group is currently stationed. Each terrain card has certain characteristics that affect the group in general and also the actions made to/from that group.
Attached is a very good description of the game by Jeff Paul