Diplomacy & Campaign AI

This guide is here to help those new to DeI 1.2 with the various Campaign AI (CAI) and diplomacy changes. A lot has changed in 1.2 on these fronts and it can be frustrating when you don’t understand the system and why certain decisions and changes were made. This guide will be an attempt to explain the system and give some tips on how to navigate diplomacy in 1.2.

How does Rome 2 CAI and diplomacy work?
In order to understand why we have our system the way it is, we need to start at the foundation of the systems in the game. At its core, Rome 2’s CAI and diplomacy are random. Period. Full stop. This has huge ramifications for campaigns because in any given campaign you could see all types of behavior and choices made by the AI. Sometimes they are bad choices, sometimes they come from nowhere and (hopefully) sometimes they are smart. The game itself has so many possible situations with so many factions, bonuses, modifiers, variables, etc. that it’s impossible to determine in any given campaign what exactly will happen on a turn.

Because of this random nature, any given turn can have different results even if replayed. If you end a turn you may see Faction X declare war on Faction Y or Faction Z break its treaties with you. You could even see another faction offer some random agreement that turn. If you go back and load the save and end turn again, you could easily see completely different things happen. Some of the same may happen, none of it may happen, or totally different results may occur. These differences are the essence of the random nature of Rome 2.

This randomness or “dice roll diplomacy” is both a good and bad thing. It’s good because it means that there are unexpected things that happen in campaigns and campaigns can be different on replaying them. It’s bad because across the many thousands of DeI campaigns, there will be times when the AI does stuff that doesn’t make sense or even seems poorly balanced or designed. In order to attempt to add some level of smart AI to the decisions, we have variables we can change within the system. These variables help weigh the dice roll and determine AI behavior in a given circumstance. Once again, its just a weighted dice roll not a pre-determined action.

Why the changes?
These weighted dice rolls as described above are effectively what we can change within the system. So, you may notice that in 1.2 most factions are now Aggressive in diplomacy and that overall the CAI is more aggressive. One of our chief complaints in 1.1 was that the CAI was rather passive and allowed the player to dictate the pace of play and in game actions, especially in the mid-late game. So, one of our goals in 1.2 was to improve the CAI’s activity and make it more dynamic and aggressive. It will now initiate actions, backstab, and generally be more of a nuisance for the player. In our testing, we found that the Aggressive setting really improves CAI behavior overall, but especially improves it in the mid/late game and during wartime. The AI will initiate unexpected attacks in both time and place and generally is much better about what it’s doing while at war. Basically, those dice rolls that happen hundreds of thousands of times across the many, many DeI campaigns are weighted more toward the aggressive than the passive side. This has produced an AI that will choose to make that attack or backstab more often on the whole rather than sit back and watch.

However, the change to Aggressive settings has some drawbacks. The early game is more difficult, especially for smaller factions. The AI will gang up on you, watch for weaknesses or oversights and exploit them, or generally wait for an unexpected moment to declare war. Things can snowball a bit if you are seen as a good target. On one hand that’s a good and realistic thing and helps the AI behavior on the whole, but on the other hand, it can be frustrating as the player. We chose to have a more aggressive AI because the benefits outweigh the negatives. Our choice was between an AI that can sometimes be randomly too aggressive in a given campaign vs. an AI that is almost always too passive. If we want the AI to be able to backstab and be dynamically active in a campaign, we have to accept that it will sometimes do these things at moments that are annoying or strange.

General Tips
– Until you get used to the new system, I highly recommend playing the campaign on Normal. For some larger faction starts you may want to try Hard, but overall Normal is what the aggression is balanced around. If you play on Hard, you can expect a lot more war declarations, backstabbing and general AI jerkiness. Also, the AI gets a lot more bonuses on higher difficulties.
– There are two submods that can help out immensely depending on your preferences and what factions you play. The Hardcore and Softcore submods have CAI only versions that will turn up or down the aggression, depending on your choice. Some players like to use the Softcore submod for small or difficult faction starts and then turn it off as they go. Others may use the Hardcore submod later in a campaign as the late game may become easier for some factions. Its even an option to start on Hard difficulty but use the submods as you go since you can’t change campaign difficulty but you can turn on/off the submods.

Diplomacy Tips
– Factions have a large starting treasury for a reason in 1.2. Yes, we got rid of a lot of the hidden income, but its also there to help with early diplomacy. Use some of that starting treasury for gifts to secure some basic agreements from other factions. Then, use money to improve those agreements. Start with a Non aggression or trade agreement and work your way up to higher agreement levels.
– Going along with that idea of money in diplomacy, be active in diplomacy from the first turn! In previous versions of the mod and in vanilla, you can almost ignore diplomacy until you need to exploit it. But, in 1.2 you have to actively engage in diplomacy from the start. You may even find that offering a faction a certain deal will have them return with another deal you didn’t expect. If you ignore diplomacy you will find yourself behind other factions that have engaged in it early on.
– Choose your allies and your enemies carefully. Do not try to ally with every single faction you meet, be careful about what agreements you make and with whom. Allying and trading with everyone may seem like a good idea, but it can lead to instability in your agreements as those factions will not all like one another.
– Check out how factions feel about one another and use that to your advantage. Join the wars of those you want to ally with for a large bonus to them. Be careful about making allies with the enemy of your friend or making enemies with the allies of your friend.
– Do not declare war or antagonize larger factions (ie Seleucids!) in the early game. Pay them off to improve relations. If you get on the bad side of a big bad, expect other factions to distance themselves from you.
– If you have a diplomatic negative as a faction trait, its going to matter, especially in the early game. Be careful about those factions that may have a negative view of you and try to stay neutral or above with them. Maybe even cultivate relationships by joining wars, using money, etc.
– Expect the AI to betray you. Alliances are just an agreement not to go to war at that moment in Total War . If the AI sees a weakness or just has a bad hair day, they may break up your love affair and come marching across the border. Try to keep some defensive forces at key spots to show the flag.