|Size||2 x 2|
|Unlocked||Level 5, Unique|
|Reward for Raiding||1|
|Reward for Occupation||4|
- "Your 'Battle Readiness Flag' signals your willingness to engage in battle with other players. Raising the Pirate flag allows you to attack other players for rich rewards, but will also allow other players to attack you. Raise your Imperial flag when you don't want to fight with other players anymore."
- — In-game Description
The Battle Flag or Battle Readiness Flag is the control center for PvP (Player versus Player) combat and is required to be built in the mission "Live Fire Training". It determines whether the player can Raid/Occupy other Outposts in their Friend List or not.
There are two options when opening the Battle Flag menu: "Attack Friends!" and "Stop Fighting!". Selecting "Attack Friends!" enables the player to Raid and/or Occupy other players' Outposts in their Friend List for various resources. Selecting this option will also turn the player's Battle Flag to a Pirate flag (), signalling that the player can attack and be attacked by other players. Any defenses or garrisons on the player's Outpost are always active, but they can be destroyed by a strong enough opponent. Defeated units are sent to the player's Hospital or Repair Bay.
Selecting "Stop Fighting!" stops the player's Outpost from being able to be attacked by other players, however, existing occupations on the player's land left by other players remain until they cycle out or are defeated. Selecting this option will turn the player's Battle Flag back to an Imperial Flag () and also prohibits the player from attacking other Outposts.
Players may only possess one Battle Flag at any time and it cannot be sold once it has been built.
- Although one Battle Flag is allowed to be built, Marin has two flags.