Diplomacy makes strategy games feel alive. No matter how many barbarian hordes invade your borders nor how cunning their attacks are, without a leader who you can talk with to negotiate a potential ceasefire the enemy simply does not feel real.
We wanted to make Aggressors feel realistic, so we tried to bring some "life" into diplomacy. Interactions with an AI cannot replace the nuances of a communication between two human players, but if you give the AI a number of tools that it can use whilst following its own goals then the interaction suddenly feels much more real.
If we look at the diplomatic possibilities in the real world, we see that some countries forge military alliances to protect their interests, other states look for "business partners" to avoid trade barriers, and yet other nations cooperate on intelligence. In short, the forms of these partnerships can be quite unique and they cannot be simply labeled by one or two words like "vassal" or "ally".With this in mind we started to design our own concept of diplomacy.
Diplomacy was for us an extremely important feature right from the start and work on it never stopped. The concept has been modified and expanded throughout the whole development of the game and the possibilities and range of diplomatic actions were greatly expanded over time. We also paid a great deal of attention to historical sources and compared them with our design and the behavior of the AI. The game should follow historical reality as much as possible and therefore mutual relations of individual states were carefully reviewed and adjusted.
There are now 11 types of bilateral agreements called treaties that work independently of each other. These include simple ones such as tile, city or unit visibility or more complex ones such as map exchange, support in supplying your ally’s units or agreement to let foreign traders through your sovereign territory. Each of these treaties can stand on its own or be combined with others which allows both the AI and the human players to create unique relationships with every opponent.
A clever combination of treaties can have numerous benefits. For example, if you want to invade lands that do not directly border your country you can sign a map exchange and shared supply agreement with the country you would need to cross with your armies. This way you will acquire information about the lands and terrains you need to cross and will be able to prepare your units in advance. The shared supply agreement will ensure that you don’t need to spend time and resources on maintaining long and vulnerable supply lines but you can use the hospitality of a friendly state instead.
Two of these treaties offer a real military and political alliance - Defense pact and a pact called "Brothers in arms". This is far more complicated than a simple agreement that allows foreign units through your country. These two alliances are a pledge that you will stand by each other's sides in defense of your lands as well as in offensive military campaigns. Such alliances can have a profound impact on your foreign policy and the position your empire holds on the global stage.
Treaties and alliances allow states to enter into a number of agreements that suit their current needs and to create very unique and pragmatic connections that can further strengthen their mutual bonds. Most importantly, such agreements are forged between AI players as well, as they also follow their own interests and plans.
Historical sources also inspired another important diplomatic feature - the possibility to merge two or more states. There are 3 options:
Confederation – union created on the diplomatic level where both states follow the same foreign policy but each maintains control over his own army and economy.
Federation– union based on sharing the same foreign policy, military and economy where one state is always a “leader” and the other a “member”.
The quantity of factors the AI player examines when entering into such a union or when considering remaining in one is quite long. Starting from the happiness of citizens and history of mutual relations, through the power of the army, successful military campaigns and territorial gains to abundance of resources and general development of the state infrastructure. Both of these unions can be revoked by either side after which both states regain their independence within the same limits as they were before merging. Therefore, when you misuse the trust of your partner by exploiting his resources, units or citizens to your own goals, friendly cooperation can soon turn into a sour experience with long-lasting consequences.
Absorption – union when one state effectively takes control over another state based on a voluntary mutual decision. This type of union is irrevocable.
All these features would be useless without an AI that knows how to use these tools to its own advantage and which can react logically and promptly to the actions of other players. In Aggressors you must keep in mind that every action can affect your foreign relations. Signing an agreement does not mean that your back is covered for good. Relations keep developing according to events and personal experiences. Even if the consequences are not immediate or substantial, there might be a slow deteriorating attitude of the other players towards you, and you might suddenly face a situation when you look to friends for help and you get only a wall of silence and rejection in response.
A minor border incident and a painstakingly built peace is shattered, and trust is ruined for decades. On the other hand, friendly gestures and actions can instigate mutual loyalties and trust that can forge strong and lasting bonds.
The attitude of one player towards another is determined by a range of factors. Starting from the philosophy of a 'friend of a friend is my friend' (which applies for enemies, too), through mutually beneficial lasting trade deals, to natural ‘meekness’ or ‘die-hardism’ of some nations.
Deliberate hostile actions (even small ones) resonate through the web of foreign relations and could leave a bad taste in the mouth of other players for a long time. For example, using piracy to steal from your enemies naturally deteriorates already bad relations. Cowardly declaring war to a friendly state by cancelling all agreements and treaties and marching your armies right away into attack is like a warning finger for other states that maintain friendly relations with you. Their trust will be shaken and they will be wary of any proposals coming from you. Similarly, the use of ‘dirty tactics’ such as city sieges when you deliberately leave the people to starve until death or surrender, are considered dishonourable actions.
On the other hand, even gestures that appear friendly on first look, such as negotiating peace after a long war, might not lead to positive results. For example, forcing another state into submission in this way might give you the false certainty that the situation has been contained but in reality, the enslaved nation will nourish their feeling of injustice and when the time is ripe they might hit back with a destructive force.
Diplomacy often mirrors the personality of the sovereign ruler and we wanted to reflect this in the game. We tried to give the nations in the campaign map a "personality" based on historical facts. The personality for example includes natural aggressiveness, which makes the AI courageous and willing to go into risky military campaigns (Pyrrhus of Epirus was a great example).
Another “trait” might be the willingness to join forces and fate with another country. This behavior has two levels – global, which means that the people in general do not have a strong national feeling and seek a strong protector, and player-to-player level which only affects particular relations (e.g. Massilia was an ally and trading partner of Roman Empire and it was opened to many proposals from the Romans, but not so much with Carthage, Rome’s arch-enemy).
The campaign's initial setup also tries to simulate historical relations between states. Whichever nation you choose to lead you will need only couple of turns to realize who your friends are and who are potential threats. The rolling ball of historical events will suck you into action right from the start.
Let's talk about some more historical aspects of the campaign map in one of our next dev diaries.