Mega Man Battle Network is a real-time tactical RPG. To progress through the game the player must alternately navigate the outside world as Lan Hikari and the Net as MegaMan.EXE, each containing certain tasks that must be completed to allow advancement in the other. Controlling Lan, the player may travel around the world map, interact with non-player characters, check email, purchase items, initiate Net missions, or speak with MegaMan.EXE through his PET.
In contrast with traditional Mega Man entries in which battle and movement through the levels happen in the same setting, Battle Network's combat occurs only through by battling computer viruses within the Net. This cyber world is represented by a series of branching pathways and nodes, where MegaMan.EXE can travel to both new and previously visited locations, find and purchase items, and fight viruses. Battles do not generally appear on the field screen of the Net but are usually set as random encounters.
The battlefield itself is made up of 18 tiles divided into two groups of nine, one group being space in which MegaMan.EXE may freely move and the other group being space inhabited by enemies.Akin to other Mega Man games, MegaMan.EXE possesses an arm cannon called the "Mega Buster". The player can transition among the nine provided tiles and fire the Mega Buster at enemies from across the screen. The objective of each battle is to delete all the viruses by reducing their hit points (HP) to zero. If MegaMan.EXE's own health depletes, a game over occurs. Certain power-up programs can be found that upgrade MegaMan.EXE's HP, defense, or Mega Buster power.
