These are the structures so far for Siege. Wizard's tower, Keep, tower, guard tower, angle tower, gate, and wall section. When setting up they may be placed beside each other or lock together with a pin. Any gaps in the wall will allow troops inside. All sections fit together in an equal square but may also be angled with the angle tower. Currently I'm finishing the rules and they will be posted on my Facebook page (not sure how to post here).
This is the smallest complete fortification possible. The objective is to protect the keep or the battle is lost. Incomplete fortifications may be built to save on points but troops may sneak through undefended areas.
Orcs siege a castle! Depending on the scenario each team would have a castle and an army. Structures cannot attack unless manned with troops, cannons, magic, etc.