Add to the list of constructions:

*Fortification (building)
**Cost:
***Average guys:
****Initial Cost: 10 Grain, 5 Metal
****Cost per Period: 15 Metal, 2 Grain
****Periods: 3
***Robots:
****Initial Cost: 10 Petroleum, 5 Metal
****Cost per Period: 20 Metal, 2 Petroleum
****Periods: 2
**Effects:
***The effect of any attack made upon a country in a territory in which ey have a Fortification is halved, rounding up.  For instance, a Crusade will reduce the defending presence by one-half (rounding up) of the attacking presence, and the attacking presence by the original defending presence.
***A fortification can be built in a territory in which is occupied or disputed, so long as the builder has a presence in the territory.  If this is the case, the controller of the Fortification shall be noted after the name of the fortification.  If the controller of a fortifcation ever no longer has a presence in the territory, the fortification is destroyed.