Units may issue the behind
command to declare whether they will
line the front or the rear in battle. Rear units do not become targets
for the enemy until all of the units in the rows in front of them have
been killed. Only missile fighters, such as archers, may attack from
the rear.
The leader of each stack (the top-most unit in the stack) will be the
last unit to receive hits, regardless of its behind
status.