Roman diplomacy, management
Roman diplomacy is more complicated than the regular kind. As there are four Roman factions (including the Senate and People of Rome itself), and all are in unbreakable alliances at the beginning, and the Senate is constantly interfering in affairs, more planning is needed before engaging a course of action.
For starters, until a faction gains enough popularity with the people of Rome, the alliances between the four factions cannot be broken. Secondly, the Senate is always encouraging expansion for each faction in a different direction. The Julii expand North and West, the Brutii strike out East, the Scipii take the South.
The Senate also has a “Policies” submenu which suggests courses of action. There is little in the way of consequences for defying the Senate, but some do exist. Should you say… negotiate a city away from a different Roman faction, the Senate will confiscate a great deal of money in retribution. Furthermore, the Senate gets quite unhappy if you encroach on the territories of long-term allies, or start wars where it doesn’t want a war. This unhappiness translates into fewer rewards and Senate offices. Weigh the benefits of defying the Senate carefully, especially early in the game where there is little need to defy it. Finally, be careful about who you ally with as the Romans. The Julii AI often makes the mistake of allying with Spain, an alliance the Senate covets. This leaves Spanish territory out of Julii reach and forces them into less lucrative lands to the North.
To gain popularity with every day Romans, all the player need do is conquer. At about 30 provinces under your thumb, Romans will be happy enough with you that you can start the Roman Civil War. The Civil War ends when one of the factions has 50 provinces, including that of Rome itself.
Popularity with the Senate translates into Senate offices and rewards for completed missions. To gain and maintain popularity with the Senate, the player just needs to complete its missions and abide by the Senate’s policies. Of course, not all these missions are good for your faction. The Julii, for example, are often stretched thin fighting the populous and wealthy Gauls, yet the Senate calls upon them to take their underpowered navy to blockade Greek, Carthaginian or Macedonian ports. All three of these powers develop navies far stronger than what is worth fighting for, and after taking Corsica and Sardinia, the Julii player has little reason to fight Carthage.
Senate rewards vary. The mission description will usually hint at what the reward is. A “minor exotic unit” is typically a mercenary phalanx or cavalry. “Greatly rewarded” missions result in 5,000 or 10,000 denarii, and so on.
Upon reaching a certain level of success, a faction becomes suspect in the Senate’s eyes. It’s too powerful to control, and even if the faction follows all Senate missions and diplomatic guidelines, sooner or later the Senate will demand the suicide of your faction leader. If things have reached this point, there is little reason to continue playing nice with the Senate, as it will continue to demand the deaths of your faction leaders at an ever-increasing pace.