There have been special rules added to reflect finnish tank fright, capture of russian AT units, forts, ice roads. It can be seen that BotS is desended from the Just Plain Wargames line of games, slightly larger with much nicer graphics. Their are 3 types of chits Full, choice and half. Full gives a full move fight impulse to the player and a chance to recover artillery previously fired in the turn. Choice gives the choice between Move and Attack.
Attack gives attacks and artillery bombardment but no movement.
Move gives full movement but no attacks. Half allows half movement or a chance to attack on a die roll of 1-3, else nothing happens at all. As each chit is draw a player executes his chosen option. The Finns counter to this is to use their better movement allowance and greater number of impulses to encircle and cut the road based supply lines of the Soviet units, which cuts their defense strength in half versus the unsupplied Finns defense strength being lowered by 1. The game system is well designed to showing a powerful but ponderous Soviet force versus a very nimble and lighter force of Finns.