This requires two very cooperative human players, and a Live connection (or two profiles and a split screen co-op game).

1 // In the Inventory Lobby, invite a friend.

2 // Start the level (use 1.2 to make it easy). Have the host hand items (Rotten Eggs, First Aid, Ammo) off to the guest for duplication.

3 // With a full inventory, have the guest leave the game (it should say "All unsaved progress will be lost" -- select "Yes").

5 // After selecting "Yes," another question for the guest will appear asking whether or not to save status and ammo. Choose "Yes" to save and you will have all the passed-on inventory saved.

6 // Now, back to the host: Quit out of the game, but at the second question, choose "No" and do not save ammo and status.

7 // Restart the game with the two characters and you'll both have the ammo and items. Duplication successful! (Note: You cannot do this with weapons as you cannot hand them off to your partner.)

Addendum: A popular money-making strategy involves duplicating Gold or Rotten Eggs. These are worth $2,000 a pop, and 5 can be crammed in each inventory slot. That means you can eventually be duplicating $90,000 each time. Finding Rotten Eggs can be tough; they drop randomly from enemies in later levels. Also, for two people to increase the amount of eggs quickly, you'll have to pass them back and forth, alternating who is saving and who isn't. Finally, you may request eggs from the computer once the guest has quit out to make this process faster.

Clear the game once with Chris "Six Pockets" Redfield to unlock Sheva Alomar's Story.

Beat the game on Veteran difficulty to unlock Professional difficulty.

Beat the game once on any difficulty to unlock Mercenaries Mode.

To unlock unlimited ammunition for a weapon, fully upgrade all of its attributes, complete the game (all chapters) and buy the ability using Exchange Points from Bonus Features (for that weapon only).

Fully upgrade the weapons listed below for the desired uber weapon:

• M92F Pistol - Unlocks the Beretta 83R (Burst)
• S&W M29 Magnum - Unlocks the S&W 500 Magnum
• Ithaca M93 Shotgun - Unlocks the Hydra Triple Barrel Shotgun
• VZ61 Machine Gun - Unlocks the Gatling Gun (for Chris only)
• S75 Rifle - Unlocks the Longbow (for Sheva only)

Beat the game on any difficulty to unlock The History of Resident Evil.

To unlock additional characters and costumes in Mercenaries mode, you'll have to do well on each level.

• Chris (Outfit 1) - Achieve an A Rank (or better) in The Village
• Chris (Outfit 2) - Achieve an A Rank (or better) in Experimental Facility
• Jill (Outfit 1) - Achieve an A Rank (or better) in Ship Deck
• Jill (Outfit 2) - Achieve an A Rank (or better) in Public Assembly
• Sheva (Outfit 1) - Achieve an A Rank (or better) in Ancient Ruins
• Sheva (Outfit 2) - Achieve an A Rank (or better) in Missile Area
• Wesker (Outfit 1) - Achieve an A Rank (or better) in The Mines
• Wesker (Outfit 2) - Achieve an A Rank (or better) in The Prison

To unlock the Rocket Launcher with unlimited ammo, beat the game in under 5 hours (on any difficulty). Note: this must be toggled on under "Bonus Features."

Unlock the following filters by performing the actions below:

• Classic Horror Filter - Beat the game on Amateur
• Retro Filter - Beat the game on Normal
• Noise Filter - Beat the game on Veteran

These additional costumes for use in Campaign Mode can be unlocked by performing the following actions:

• Safari Chris - Complete all chapters
• Clubbin' Sheva - Complete all chapters
• Tribal Sheva - Complete all chapters and find 30 BSAA Emblems
• S.T.A.R.S. Chris - Complete all chapters and find 25 BSAA Emblems

You can unlock the following objects for your space in Home by performing the actions listed below:

• Albert Wesker - Complete the game on Professional difficulty
• Chris Redfield - Sign in to Home (automatic)
• Jill Valentine - Complete the game on Veteran difficulty
• Sheva Alomar - Complete the game on Normal difficulty
• Treasure Chest - Collect all treasures in the game

Below is a list of the unlockable characters for Versus Mode (downloadable content) and their costs in the game's exchange points.

• Safari Chris - 8,000 points
• S.T.A.R.S. Chris - 13,000 points
• Clubbin' Sheva - 6,000 points
• Tribal Sheva - 15,000 points
• BSAA Jill - 5,000 points
• Battle Suit Jill - 7,000 points
• Midnight Wesker - 30,000 points
• S.T.A.R.S. Wesker - 50,000 points

Unlike in Resident Evil 4, your ammo and money carry over every time you replay a level. Collect money and ammo in a chapter; then pause, save and quit. Restart the chapter and you can collect everything a second time. This works well in chapters 1-2, 3-1 (the hovercraft level) and 4-1 (caves). As a general rule, this "farming" method works especially well in levels in which you can collect weapons worth money and ample hidden treasures like jewels and beetles. For instance, 3-1 has copious amounts of treasures, and a Rocket Launcher on the sunken boat that you can repeatedly collect.

Below is a list of how many BSAA Emblems can be found on any given chapter in the game. There are thirty emblems total, and not each chapter has one.

• Chapter 1-1 - 0 Emblems
• Chapter 1-2 - 3 Emblems
• Chapter 2-1 - 5 Emblems
• Chapter 2-2 - 3 Emblems
• Chapter 2-3 - 0 Emblems
• Chapter 3-1 - 4 Emblems
• Chapter 3-2 - 2 Emblems
• Chapter 3-3 - 1 Emblem
• Chapter 4-1 - 3 Emblems
• Chapter 4-2 - 1 Emblem
• Chapter 5-1 - 1 Emblem
• Chapter 5-2 - 1 Emblem
• Chapter 5-3 - 3 Emblems
• Chapter 6-1 - 3 Emblems
• Chapter 6-2 - 0 Emblems
• Chapter 6-3 - 0 Emblems

When using the unlockable character Wesker in Mercenaries, you can click the Right Analog Stick (sometimes called R3) to initiate a dash. Press R1 + R2 while dashing to do a knee attack. Warning: This move will drain your own life meter, so use it sparingly!

In Mercenaries mode, ammunition drops are based on the type of weapons you have. Use this to your advantage by discarding weapons you don't use. This causes more ammunition to be dropped for other weapons. Example: For Wesker (Stars), drop the Samurai Edge to find more Magnum and Shotgun ammo.

In Mercenaries mode you can reload your weapon by pulling up your Inventory screen and combining the ammunition manually with the gun (using the "Move" command button). Once you get used to this, you can use it to your advantage since it is a lot faster then reloading your shotgun, for instance, on the fly. More importantly, you can use this trick while climbing a ladder or when you are a jumping down to really save some time -- and possibly your neck.

Below is a full list of weapons and how to find / unlock them. Most can be found in silver suitcases. The Dragunov is in a locker. Others are bought after fully upgrading a weapon.

Handguns

• M92F - Chapter 1-1
• H&K P8 - In Store after Chapter 3-1
• SIG P226 - In Store after Chapter 5-1
• M93R - Fully Upgrade M92F

Shotguns

• Ithaca M37 - Chapter 1-2
• M3 - Chapter 3-3
• Jail Breaker - Chapter 6-1
• Hydra - Fully Upgrade Ithaca M37

Machine Guns

• ZV61 - Chapter 1-1
• AK-74 - Chapter 5-1
• H&K MP5 - Chapter 2-1
• SIG 556 - Chapter 5-2

Rifles

• S75 - Chapter 2-1
• Dragunov SVD - Chapter 2-2
• H&K PSG-1 - Chapter 5-3

Magnums

• S&W M29 - Chapter 3-1
• L.Hawk - Chapter 5-3
• S&W M500 - Fully Upgrade S&W M29

Special Guns

• Gatling Gun - Fully upgrade ZV61 and beat the game
• Longbow - Fully upgrade S75 and beat the game

You can click both analog sticks to taunt or goad nearby Majini into coming at you instead of your partner. Have your shotgun ready. "C'mon, c'mon!"

If you get invited to play a level on Professional via PSN with someone who has unlocked Professional Difficulty in their game, it will then be unlocked in yours.

To acquire the Infinite Rocket Launcher, you must achieve a total game time of under 5:00:00. You don't have to play the game all the way through in one run to get a low total time -- you can just go chapter by chapter, using the Chapter Select, lowering your time in each. Your final time is a total of your lowest runs through the chapters.

When the melee option appears, reload your weapon. Then, activate the melee sequence. The weapon will be reloaded instantly (and the enemy out of your face).

Upon starting this level you'll be able to climb to the top of the crow's nest to the left of your spawn point. From here you may snipe the enemy that operates the crane. Look for him under the arm of the crane by the controls to the upper left. This will allow you to skip the scene in which your partner gets trapped in the cage. You can also snipe the enemy half way up the ladder, and the one by the caged area. The latter is easier to shoot from the level's initial starting point.

Once you unlock unlimited ammo for a gun, it will be unlocked for all copies of that gun you may have. Buy one for your partner so they can join in the fun! Note: You'll still have to fully upgrade any additional weapons to get their maximum power.

At the very end of 2-1 you'll ascend a building before fighting the chainsaw-wielding maniac. At the top of the building, you are prompted to split up so Sheva can work her way to the other side of the locked door below. You can avoid this entire scene and stay together by unlocking this door in an alternate way.

Alternately, if you have the Gatling Gun, you can push it through the door and it will shoot off the lock from the other side.

If you have ammo or other pickups at your feet, you can use them to evade enemy grabs and other attacks. Simply initiate the item pickup as the enemy begins its attack animation. You’ll be invincible as you bend down. Your AI partner will temporarily remain invincible as well. This can save your life in Mercenaries!

There is a special treasure to be had in the boss fight with Jill and Wesker. If you beat up Wesker enough in the seven minutes he has to spare, the Heart of Africa treasure will appear between the two stairs on the bottom level -- behind where Jill spawns during the second half of the fight (and you can pick it up in the second half too). One Rocket in Wesker's well-groomed face will do the trick (you have to shoot the rocket with another rocket or a gun while he holds it). Hide at the end of a long passage after he kicks you through the wall. Soon you'll see on your map that he's spinning around, looking for you. Shoot him with a rocket then.

Note: This is significantly easier with unlimited ammo. After encountering your first Majini and jumping out the window in Chapter 1-1, a long wave of Majini will stream out of an alleyway. Instead of running for safety, take them on. After 20 or so, a final one will leave behind the Topaz (Marquise).

Its pretty easy in a way. 1st you go to 5-1 and just run to the part where you face two lickers. Kill one of them and and shoot the surviving one with a shotgun until he's on his back then run up to him and press square. This is really easy on veteran with a handcannon and a shotgun with unlimited ammo. It is easiest on professional.

If you wait around long enough at the very beginning of Chapter 1-1, before any checkpoints, you will trigger a conversation between Sheva and Chris in which Chris gives a scathing critique of the American Dream.

At the very start of Chapter 1-1, take your first right just past the building and you'll see a quick cutscene of a fellow in an unfortunate predicament.

In this immensely stupid Easter Egg, Chris and Sheva can take a short rest in a chair. There are chairs in Chapter 5-3 (at the beginning of the chapter, far end of the lab) and Chapter 6-2 (the captain's seat). That is all.

In the third part of Chapter 2-2, look for a green portable toilet just past the truck with a gatling gun. Politely knock on it for a surprise. Oh, and have a weapon ready.