Any movement from or to one of your territories can be intercepted, by sending troops to meet travelers. The coordinates depend on the trajectory and the movement rate of the units. It is not possible to initiate the interception of a movement that would end before the interception can take place. Moreover, if the intercepted units come from different places, it is possible that they can not all be intercepted at the same time. The interception action triggers a new movement towards the meeting point, regrouping the intercepted units and the intercepting units. This meeting point will always be on solid ground, in an empty and freely accessible territory; if intercepted at sea, units will automatically move to the nearest coast.