Successfully complete the game on any difficulty setting with any ranking. Then, battle mode will automatically be saved to the memory card and selectable at the main menu.

Successfully complete the game on the easy or normal difficulty settings with any ranking to enable an option to play battle mode in first person view.

Get an "A" ranking with Chris, Steve Burnside, Albert Wesker and both versions of Claire in battle mode to unlock the linear launcher. It will appear in your inventory during the next battle mode game.

Take Albert Wesker's sunglasses from the floor in the Incubation Lab after the intermission sequence when playing with Chris. Alternately, perform well in battle mode with Steve Burnside.
Perform well with the original Claire in battle mode.

Get the Gold Lugers from the basement office in Disc 2. The correct combination is red, green, blue, and brown. You can also unlock Steve Burnside by performing well with the original Chris in battle mode.

Steve Burnside cross-fire with sub machine guns

While playing in battle mode, kill all but one zombie in any room. While equipped with sub machine guns, walk up to the zombie and press A, and Steve will cross his sub machine guns. For best results, play in third person so you can see the cross-fire. If there is more than one zombie,

Steve might aim at two zombies rather than cross-firing at one.

Get an "A" ranking in the normal game by completing it without saving, no first aid sprays, and no retries. Additionally, save Steve from the Luger quickly, give the Medicine to Rodrigo, and complete the game with a time less than 4:30. The rocket launcher will appear in the first item box in the next new game.