Your Presence and ability to control the Underdark is represented by your forces: the troops and spies you’ve placed on the game map.

Presence
Most actions you take on the game map require you to have Presence where you take the action. You have Presence...
• At any site where you have a spy, a troop, or a troop in a space adjacent to that site.
• At any troop space on a route if that space is adjacent to a site or space where you have a troop.

 

Find out more here...