Capture (also known as "capping") is a Command. It is used by Infantry, Mech and Motorbike Units. It allows them to Capture a Neutral or Enemy Building. Capturing enemy Buildings should be given priority over capturing neutral buildings to also deprive the opponent of funds .
A building has 20 HP which needs to be lowered to zero before it is captured. After giving a unit the capture command its HP is deducted from the amount of HP left on the building. Thus Buildings can be captured within two days if the infantry has full health (10 HP). A unit with only 1HP will then take 20 days to capture a property.
Should an infantry unit be destroyed while capturing, that building's HP will return to full.
Using a Tag Power allows you to give two commands to all of you units in the same turn. This can be used to capture a property in one turn or join two units together first to allow for a faster capture rate in subsequent turns.
Contrarily, the CO power of Green Earth CO Eagle does not give this opportunity as his power does not include infantry units.
Orange Star CO Sami allows for faster capture as each infantry unit has a 150% capture rate, rounded down. Additionally, from Advance Wars 2 onward her Super CO power grants every infantry unit the ability to capture properties in one turn, regardless of condition.
Capturing is a vital part of offensive strategy. Captured buildings provide fuel, ammunition, funds and reinforcements, allowing armies to be less dependent on the starting base and units. While providing benefits to you capturing buildings also denies them to your opponent, even in a perceived upper hand it's always a good idea to keep taking over enemy properties to decrease the chance of being fought back.
Conversely, it is vital for players on the defense to prevent captures of their own buildings. Attack capturing units or destroy them beforehand and preemptively place units on buildings to prevent speed/sneak captures.
A particularly potent strategy is sneak capturing. Using transport helicopters, APCs, or landers, players can allow their infantry to travel at much greater distances than otherwise possible. Using the cover of Fog of War , transport units laden with infantry or mechs can sneak behind enemy bases and capture production buildings, cities, and particularly HQ's. The latter instantly ends a game in the user's favor.
This strategy is often successful during the mid-to-late game, where players often neglect to train more units at their home bases, prefering to train units at captured buildings closer to the frontline. Should players have no units within range of the targetted buildings, they have no way of saving them unless they make it by using their Tag CO power.
It is fairly simple to prevent HQ sneak caps: place units on the HQ, preferably something strong against infantry and mechs. Preventing factory/airport/port capture is more difficult, as keeping units on them prevents them from producing units.