The victors move 2D6" forward directly after their withdrawing enemy. If they roll greater than their enemies' Fall Back score they catch and destroy them. This represents the victors shooting the enemy down as they retreat, scattering them beyond recovery, and generally jumping up and down on their corpses.
Units advancing into, out of or through difficult terrain only move half the distance rolled on 2D6.
If a unit is pursuing a foe who falls back off the board the pursuing unit will stop when it reaches the table edge.