Please post this additional clarification for my game Vallee de la Morte. Thanks! LOS/LOF for artillery units is traced through contiguous, unoccupied areas, up to the limit of the firing unit's range. Direct fire weapons, such as infantry, tanks and AA, must trace LOS/LOF with a straight edge as described in the rule. This compromise accounts for the indirect nature of these weapons' trajectories, without additional rules for height and spotting. Enjoy! Paul Rohrbaugh