Lions of the Atlantic, while open-ended by nature, is also a bit structured. That is, there is a plot that you can follow as you go along, although you can choose to ignore it if you want.

There are three types of missions in the LotA world:

* Story missions: Missions that have to be completed to continue. They may have up to five Goals each, and are accompanied by journal entries or letters describing the situation.

* Bonus missions: These missions do not have to be completed, although they give you healthy rewards if you finish them. They are shorter than the story missions, with up to three Goals per mission, and flesh out the story and world.

* Ruler missions: These missions are short affairs, with small rewards, given to you by the rulers of various ports. They vary in type and difficulty, and have no bearing on the story. They can consist of up to two Goals.

Goals are the "meat" of a mission. A Goal is a specific task that you have been charged with, of one of the following types:

* Deliver message to X city

* Amass X units of Y

* Kill X

* Kill X # of Y country's fleets

* Deliver X units of Y to Z

* Bring X units of Y here

* Escort X to Y

* Go to X

In addition, all goals may come with a time limit, and all goals may have the stricture "while avoiding enemies," which, in general, means that there will be a lot of pirates in the mission area.

Of course, these missions can have various effects on the rulers affected by them, from inciting wars to making you the most trusted captain in the Atlantic. It will be up to you to carry out these missions, or to deal with the consequences of ignoring them.