Fortress/Ultima Ratio

==Available technologies==
===Fortification ===
====Trace Italienne====
New defences to blunt newer weapons.
*Castles are stronger, have greater range and can garrison more units.
*Prerequisite for Fortress
Cost	Requirements	Leads to
*150; 120
*Time to complete: Long	
* 
* 	
*
*
The Measuring Tools requirement automatically limits the construction of Fortresses to the Mercantile Era and beyond.
====Polygonal Architecture====
A modern variation of an ancient theme to frustrate future foes.
*Castles and Fortresses are stronger, have greater range and can garrison more units.
*Required to access Citadel
Cost	Requirements	Leads to
*350; 240
*Time to complete: Long	
*
* 
*  	
* 
*
The use of Tariffs limits use of Citadels to the Imperial Era and beyond.
===Strategy===
====Subterfuge====
In the world of espionage, lies and truth are interchangeable to all save the wary and alert.
*Buildings build faster
*Buildings have added hitpoints
Cost	Requirements	Leads to
*50; 70	
* [2]
* 	
*
*Agent
====Secret Service====
"So then, who were you working for?"
*Buildings build faster
*Buildings have added hitpoints
Cost	Requirements	Leads to
*100; 170	
*
* 
* 	
*
*(Aerial Warfare Doctrine)