The term lord refers to any character who holds at least one estate, but is not the ruler of a realm.
This is a middle rank in any hierarchy, above the knight but below the rulers. It is perfect for players who are interested in economy, trade and a limited amount of politics. Lords can have knights as vassals and may or may not themselves be vassals of another liege.
Keeping the Settlements under your control (your estates) running is a primary responsibility for a lord, because these settlements supply resources and soldiers to you, your vassals and your realm.
Managing an estate includes construction of buildings, roads and other features as well as trade and general economy.
The Might & Fealty world is running on limited resources, which means the primary way that settlements can grow is at the expense of other settlements, through the trade of food. The chapter on Trade & tribute is one of the most important ones for a lord.
For any larger settlement, securing the service of a few knights can be vital in both defending your estate and supporting your arguments when it comes to trade.
Finally, active buildings within a settlement are a continuous drain on resources, and the right balance and decisions about what to build and what not to can make a big difference in the usefulness of a settlement to yourself and your realm.
One of the most important things to keep in mind about your estates is that you are responsible for the permissions granted to friends and allies, and you can also use the Permission system to delegate responsibilities to your vassals or other trusted people.
Once your character has at least one vassal who is not another character of yours, you can found a realm. You can, of course, also become ruler of an existing realm by inheritance, conquest or selection (see Politics). One way or the other, as soon as you do, you are Playing a ruler.