The Support line is a major battlefield element in KARDS. The Support line is usually the starting point for all units and is always populated with a Headquarter.
How it works
Each player is in control of their own Support line (contrary to the Frontline). The Support line always holds your Headquarter and up to four additional units.
When the Support line isn't full already with four units plus HQ, you can move units from your hand into your Support line.
When the enemy doesn't control the Frontline, you can move your units from the Support Line into the Frontline.
How to attack units in the Support line
Units in the Support line can be attacked by all units in the Frontline. Units in the enemy Support line can attack your Support line units only if the are long-range units such as Artillery, Bombers, or Fighters.
Orders can damage units in the Support line.
Moving to and from the Support line
Usually, you move units from your hand to the Support by dragging a unit card from your hand onto the battlefield.
If you cannot pay the cost of deployment or if the Support line is already full, you will get an error message.
Moving units from the Support line into the Frontline is done by dragging units from your Support line to the Frontline.
Only under special circumstances (for example when issuing Orders like Tactical Withdrawal), your units can retreat from the Frontline back to the Support line. Usually, units that are in the Frontline cannot be moved back to the Support line.