Most of the time, the gangs within a local area maintain a sort of uneasy balance of power, with no single gang able to grow strong enough to oust the others. Sometimes, however, one gang may become powerful enough (at least in the mind of its leader!) to try to push other gangs out of their territory.
Download the pdf
here. This hasn't been tested, and I don't know if I got the balance of sentries right. Feedback appreciated.
