Operation Battle (オペレーションバトル?) is a feature from the Mega Man Battle Network series that becomes available with the use of a Battle Chip Gate. When used, the gameplay becomes similar to Rockman.EXE 4.5 Real Operation, with the NetNavi moving on his own while the player uses Battle Chips in the Chip Gate. In this mode, the Custom Screen is not present, and the Battle Chips that can be used depend of how much the Custom Gauge is filled. This feature is present in the following games:
- In Mega Man Battle Network 4, Operation Battle is a secret mode that becomes available in the title screen. Although the Battle Chip Gate wasn't released outside Japan, it can be used in any version of the game.
- This is the standard battle mode in Rockman.EXE 4.5 Real Operation.
- In Mega Man Battle Network 5, Operation Battle replaces the main game's battle mode when the Progress Chip Gate is inserted.
- Operation Battle is not present in Mega Man Battle Network 6, but the Custom Gauge keeps the properties of this mode with the Beast Link Gate.