Reward: The Regiment owns the ground: for the rest of the campaign, on that board (or any board sharing its terrain type), the gang may set up up to TWO-THIRDS of its fighters hidden instead of half. This sub-plot can be claimed once per campaign, tied to one district.
Own the Ground triggers once your gang has fought three separate campaign battles on the same terrain-dense board or district, learning its every hide and approach. When it does, the Regiment owns the ground: for the rest of the campaign, on that board — or any board sharing its terrain type — you may set up up to two-thirds of your fighters hidden instead of half. This sub-plot is claimed once per campaign, tied to a single district. Fight the same green long enough and it stops being terrain and starts being yours.