For limited invulnerability, mix the green, blue and red herbs in that order. You MUST mix the herbs in that order, or they will not work. Green and Blue MUST be mixed together first, then you add the red herb.
For alternate uniforms you must start a new game on medium. When you start to play don't collect any items (when your going to the Police station), before you get to the police station there's a path with an arch over it and when you are there, you will find a zombie. Kill him and pick up the key he has. When you go into the police station go to the dark room and use the key to get into the lockers and if you are Clair, you can get one uniform, and if you are Leon you can get two.
Gatling Gun with Unlimited Ammo
Complete either character's second scenario without saving the game in under 2.5 hours with an A or B ranking for the special gatling gun. The special weapon will appear in the next game after the first chest is opened.
At the load game screen, press Down(4), Left(4), L, R(2), L, C-Up, C-Down. If you entered the code correctly, the game will return to the main menu.
At the load game screen, press Up(4), Right(4), L, R, L, R, C-Right, C-Left. If you entered the code correctly, the game will return to the main menu.
As soon as the Title Screen appears, Press Down, Up, Down, Up, A, B, C-Left, C-Right, Start.
When you reach the gator part with LEON, look for a gas tank on the wall, when the gator comes out, run to it and push A. It will fall to the ground. When the gator picks it up, shoot him, it'll blow him away.
In all games, the combo for the safe in the police office id 4542. For LEON, it has shotgun shells and a map. For CLAIR it has acid rounds (for grenade launcher) and a map.
Secret Character Tofu
Performing this trick will allow you to play an extra scenario with a character named Tofu. Beat the following scenarios in this order with a B Ranking or better all on the same file: Leon A, Claire B, Leon A, Claire B, Leon A, and Claire B. Go to the "Load Game" menu and you will see a file titled "Tofu/00". Note: You must have obtained Hunk's scenario and have it saved on one of your other files in order for this to work.
Trick - Rocket Launcher
Performing this trick will allow you to pick up the Rocket Launcher with infinite rockets. Beat either character's Scenario B with a B Ranking or better without saving once. After you've done this the Rocket Launcher will appear in the next game you start inside the first chest. Note: In order for this trick to work you must start your new game over the file in which you received your B Ranking.