Trust is an important factor in AI calculations. The more an AI nation trusts the player, the more likely it is to follow them into war.
Trust is lost through declaring war, or breaking agreements. It is gained by abiding by agreements and, most importantly, honouring Calls to Arms.
It may also be possible to gain trust by fighting rebels/enemies on the target's provinces, or by besieging captured provinces to return them to the target, but these have not yet been proven. It is also believed that trust will slowly increase up to the neutral level, as long as no negative actions are undertaken.
The levels are (from lowest to highest trust level):
- They would not trust us to die properly.
- They expect us to break every deal and alliance.
- They deeply distrust us.
- They view us with distrust.
- They are willing to trust us somewhat. (this is the neutral level)
- They trust us to uphold our bargains.
- They feel we are highly trustworthy.
- They trust us implicitly.
- They trust us utterly.