Note: This game is also titled Biohazard 2 - Dual Shock. 
 
 Infinite ammunition
 
 Start a game and press Select to display the options screen. Select 
 the "Key Config" option, then hold R1 and press Square(10). If you 
 entered the code correctly, the word "Auto" will turn red. 

Extreme Battle/Survival mode
 
 Beat the game with Leon, then save the game. Then, play Claire's 
 second scenario, beat the game, and save the game.
 
 
 
 Play as Ada Wong
 
 Successfully complete level 1 of Extreme Battle/Survival mode. 
 
 
 
 
 Play as Chris Redfield
 
 Successfully complete level 2 of Extreme Battle/Survival mode.
 
 
 
 
 Bonus weapons
 
 Successfully complete either character's first scenario in under 
 two hours and thirty minutes with an A or B ranking for the rocket 
 launcher with infinite ammunition. Successfully complete either 
 character's second scenario in under two hours and thirty minutes 
 hours with an A or B ranking for the gatling gun with infinite ammunition. 
 Successfully complete either character's second scenario in under 
 three hours with an A or B ranking for the machine gun with infinite 
 ammunition. Note: The bonus weapon will appear in the next game 
 after the first chest is opened. 
 
 
 
 
 Hunk scenario
 
 Successfully complete either character's second scenario in under 
 two hours and thirty minutes with saving less than twelve times. 
 Hunk is a soldier that must reach the second floor of the police 
 station from the sewer with just battles and no puzzles. 
 
 
 
 
 Tofu scenario
 
 Successfully complete either character's first and second scenarios 
 in less than three hours. Then, play the game again with the other 
 character, and successfully complete their first and second scenarios 
 in less than three hours. Play the game a third time and complete 
 either character's first and second scenarios again in less than 
 three hours. Note: The game must be saved less than twelve times 
 during each of the six scenarios played and bonus weapons must not 
 be used. Tofu is a piece of tofu (food) that must reach the second 
 floor of the police station from the sewer with just battles and 
 no puzzles. Tofu can not use any weapons other than a knife. 
 
 
 
 
 Alternate uniforms
 
 Start a game on the normal difficulty setting. Then, go to the police 
 station without collecting any items. Quickly move past the zombie 
 that appears in the alley near the police station. Collect the shotgun, 
 then kill the zombie. Take the special key from the zombie's body 
 and go to the dark room to open the lockers with alternate uniforms. 
 Claire has a single alternate uniform, with a quick shooting revolver. 
 Leon has two alternate uniforms, one of which will allow him to 
 shoot with one hand.
 
 
 
 Auto-aim
 
 Select "Options" from the main menu or press Select while playing 
 a game. Enter the "Key Config" screen, select "Type C", then select 
 "Exit". The quick auto-aim feature should now be enabled. Hold R1 
 to get Leon or Claire to pivot and aim at any zombie they see, and 
 press L1 while holding R1 to change targets. Note: You still have 
 to hold Down to aim at crawling zombies and Up to aim at higher 
 targets.
 
 
 
 Film D
 
 Search the desk on the left side of the S.T.A.R.S. office. The phrase 
 "Its trashed someone must have searched it" will be displayed. Repeatedly 
 search the desk approximately fifty times until a roll of film is 
 found. Take the film and develop it in the photo lab to see a picture 
 of Rebecca in a basketball uniform. 
 
 
 
 
 Shoot the screen
 
 While playing Leon's scenario, take the infinite ammunition shotgun 
 and go to the roof where the helicopter crashed. Stand near the 
 door leading inside, and make sure that a close-up view of Leon 
 appears. Then, aim the shotgun at the screen and fire. Bullet holes 
 will now appear. Note: This may also be done at any location where 
 Leon can aim at the screen with the shotgun.
 
 
 
 Hidden ammunition
 
 The following locations behind and within the police station in 
 the first scenario contain hidden ammunition caches:
 
 
 
 Alleyway past the stairs of the gunshop
 
 Turn towards the trashcans opposite the blue dumpster and search 
 them for hand gun bullets. 
 
 
 Alleyway past the basketball court
 
 Go past the zombie-filled basketball court until you find a van. 
 Search the back of the van and to receive hand gun bullets. 
 
 
 
 Dark Room
 
 Search the filing cabinet along the wall (next to the storage box) 
 for hand gun bullets. 
 
 
 S.T.A.R.S. office
 
 Check behind the "trashed" desk for hand gun bullets. 
 
 Hall with the stairs to the basement
 
 Search the mop bucket leaning against the metal shelves behind the 
 stairs. 
 
 
 Night Watchman's bunk room
 
 With Leon, search the lockers for shotgun shells. 
 
 Briefing room (with the chalkboard)
 
 Using Leon, go to the room where the red jewel was hidden in the 
 painting and search around the middle of the junk pile of art at 
 the far end of the room. 
 
 
 The hall with the crows
 
 Search the man "that was pecked to death" twice for hand gun bullets. 
 
 
 
 The hall behind the main R.P.D. police office (with the safe)
 
 Look for an unmoving zombie lying face-up on the floor and search 
 it for hand gun bullets. 
 
 
 The hall with the filing room (near the beginning of the police 
 station stage)
 
 
 Check the dead zombie lying on the floor. 
 
 Filing room (with the two sided filing lockers in the middle) 
 
 
 
 Using Leon, check the middle filing cabinets for shotgun shells. 
 
 
 
 Party room (with the last surviving police officer)
 
 Search the cabinet where you talked to the last surviving police 
 officer. 
 
 
 Statue with second red ruby
 
 Have Leon or Claire search behind the statue with the second red 
 ruby. 
 
 
 
 
 Mixing herb power-ups
 
 The herb power-ups can be mixed using the "combine" command for 
 varying, but very beneficial results. This will also save storage 
 space for holding puzzle items. Here is a listing of some herbal 
 combinations and the outcomes:
 
 
 
 1 green herb + 1 green herb = 60% health recovery
 1 green herb + 1 blue herb = 20% health recovery and poison antidote 
 
 
 1 green herb + 1 red herb = Full health recovery
 3 green herbs combined = Full health recovery
 1 green herb + 1 red herb + 1 blue herb (in that order) = Cure-all 
 (full health recovery and poison antidote) 
 
 
 
 
 Ranking system
 
 Normal difficulty
 
 
 
 Under 1 1/2 hours, no saves, no first aids, no mixed herbs, no infinite 
 weapons = "S"
 
 1 1/2 - 2 1/2 hours, 1-3 saves, 1-2 first aids, no infinite weapons 
 = "A"
 
 2 - 3 hours, 1-7 saves, 1-4 first aids, no infinite weapons = "B"
 
 
 2 - 3 hours, 1-5 saves, 1-3 first aids, infinite weapons = "B"
 
 
 3 - 4 1/2 hours, 1-7 saves, 1-7 first aids, no infinite weapons 
 = "C"
 
 3 - 4 hours, 1-7 saves, 1-6 first aids, infinite weapons = "C"
 
 
 4 1/2 hours or higher, 7 saves or higher, 6 first aids or higher, 
 no infinite weapons = "D"
 
 4 1/2 hours or higher, 8 saves or higher, 6 first aids or higher, 
 infinite weapons = "D"
 
 
 
 Easy difficulty
 
 
 Under 2 hours, 1-3 saves, 1-2 first aids, no infinite weapons = 
 "A"
 
 2 - 2 1/2 hours, 1-3 saves, 1-4 first aids, no infinite weapons 
 = "B"
 
 2 - 2 1/2 hours, 1-2 saves, 1-2 first aids, infinite weapons = "B"
 
 
 2 1/2 - 3 1/2 hours, 1-8 saves, 1-5 first aids, no infinite weapons 
 = "C"
 
 2 1/2 - 3 1/2 hours, 1-6 saves, 1-4 first aids, infinite weapons 
 = "C"
 
 3 hours or higher, 9 saves or higher, 4 first aids or higher, no 
 infinite weapons = "D"
 
 3 hours or higher, 9 saves or higher, 5 first aids or higher, infinite 
 weapons = "D"
 
 
 
 
 
 
 
 
 Final stage bonus room
 
 The final stage has a bonus room that can be entered through a long 
 but easy process. In the first scenario, have Leon or Claire use 
 the red lab key card to enter the room with the giant flying moth. 
 Kill the moth. Find the keyboard attached to the wall, kill the 
 larvae on it and type your name in on the keyboard as "GUEST". Register 
 your fingerprint. Go to the first floor of the lab and find the 
 thumbprint reader panel. Use your fingerprint, and the panel should 
 then ask for a second "fingerprint verification." Complete the game, 
 and save the second scenario to any file. In the second scenario 
 from the game you have just played, go to the final stage. Find 
 the room on the first floor of the lab where wriggling plant vines 
 are blocking the vent. The red lab key card should be there. Take 
 it and go to the moth room with the keyboard. Enter your name as 
 "GUEST" and register your thumbprint. Finally, go to the first floor 
 and find the thumbprint reader. It should ask for the "secondary 
 fingerprint verification." Do it, and the bonus room to the right 
 of the panel should be unlocked. Look for a special weapon inside. 
 
 
 
 Safe combination
 
 The combination to the safe in front of the chief's desk at the 
 police office, with all the zombies, is 2236. Open it to find shotgun 
 shells and a map.
 
 
 Easy gator kill
 
 When fighting the gator, and he starts coming towards you, go and 
 inspect the yellow light on the left wall. Then, the light will 
 fall off and the gator will eat it. Now while the light is in its 
 mouth, shoot it and the gator will explode.
 
 
 Tyrant's ammuntion
 
 In Leon or Claire's second scenario, the player will constantly 
 run into a giant super zombie called Tyrant. Every time a Tyrant 
 is defeated, the player can steal his ammunition: Shotgun shells 
 or magnum bullets for Leon, and grenade rounds or bow gun bolts