Have you been starting the campaign script?
Q: What is the "campaign script" and how do I load it?
A: The campaign script is the way EB mods much of the game to introduce new features and gameplay like seasons and stuff. Loading the campaign script is easy. As soon as you start a campaign, and every time after that when you load that game click on any one of your cities. An advisor will pop up telling you to click the "show me how" button. Do this. Now the advisor can be closed if it doesn't do so automatically. Advice does NOT need to be turned on for this to work.
Sounds like you haven't. If you haven't you'll need to restart your campaign. Next time pay attention to the advisor when he keeps popping up.

If you have been starting the script each time you loaded the campaign then all information about roman reforms can be found in the EB FAQ
Q: As the Romans, why can't I build factional MICs in X area.
A: The Romans can only build factional MICs in areas that contain Roman units. The area expands based on the reform level (see below). During the Camilian Era, you can build factional MICs in your starting cities plus Segesta. During the Polybian Era, you can build factional MICs in "Homeland" regions (Italy). During the Marian & Avgvstan Eras, you can build factional MICs everywhere, but have limited recruitment, based on the area.
We need some kind of stock response for this.

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