Units will capture tiles they occupy adjacent to your Empire. It is recommended that you leave this option on, as it adds a stable yet dynamic way to gain (or lose) tiles during wartime.

• You are at war, and the enemy territory borders your territory.
• Enemy units are NOT adjacent to the territory.
• Tiles adjacent to the unit are also captured if unoccupied and border your land.
• Only land units can capture, however adjacent sea tiles can also be captured.
• Territory adjacent to Cities and Citadels cannot be captured.
• Forts and Citadels can only be captured directly (by occupying that tile).
• Capturing a Citadel will also capture all the tiles surrounding the Citadel.
• Siege and Recon Units cannot capture tiles.