In Service of Life!
All Must Serve – “Blood or Money”. The fight against the Lich Lords at North Gate Garrison is coordinated by the High King from the side of the heartlands, and in the north a loose confederation centered around the lands of Kaald. ALL vassals and allies of the High King are required to send “troops”, supplies, or money. Many send a combination of all. Each supplier has their own system for determining this. The entire populace takes the Oath of the Day Watch by the time they are 15 years of age (or equivalent).
Service at North Gate Garrison ends with those who served getting North Gate Service Signifiers.
Why Serve and/or Fight?
Why do people serve at North Gate Garrison? Because they muster out with money and opportunity. They are recorded in the rolls that mark where they came in on for later. With their North Gate Service Signifiers, they get transport back to or any destination of the same length within the lens of the Steel Realms that are at least not enemies. A lot of people choose The prestige of fighting in the north against the Lich Lords over being caught up in some local war and killed for nothing. Some choose it instead of prison, debt, or work farms. Boats going to the port on The Red March are filled with a few prisoners. But they won’t take murderers, or sex crimes. Typically only petty theft and minor transgressions.
You Cannot Remain
You are required to leave the north however. The north does not want a bunch of battle-scarred veterans loitering. There is a local martial order called The Home Garden Marshals that take reports of those that have left the wall and not gotten their mark and are not leaving and track them down and force them to leave.