To throw grenades underhanded, lightly hold the L1 button instead of holding it down completely.

To have your character sing a part of the Metal Gear Online melody, type <SONG> (case-sensitive) in the chat window during game play. Note: During the final round of the map, just when the round ends and the screen with your gameplay stats appears, sing. Your player will hum out the entire song.

Get the following rankings to appear next to your name by performing the corresponding tasks:

RANK - HOW TO UNLOCK
Bear - Have a large amount of CQC attacks given.
Bee - Uses lots of scans.
Chameleon - Prefer team sneaking rules.
Chicken - Rarely participate in battle.
Crocodile - Very good kill death ratio.
Doberman - A top-class soldier.
Dove - Perform a lot of non-lethal attacks.
Eagle - Large percents of headshots.
Flying Squirrel - Have a high percentage of rolling.
Fox - The best of the best.
Foxhound - A living legend.
GA-KO - Prefer rescue rules.
Grasshopper - Crawl the majority of the time.
Hound - A superior soldier.
Jaws - Large amount of knife kills.
Kerotan - Prefers capture rules.
Night Owl - Use the ENVG a lot.
Pigeon - Perfers non lethal attacks.
Rat - Falls for a lot of traps.
Sloth - Gets shot in the head a lot.
Snake - Perfers sneaking missions.
Tarantula - Have a lot of team kills.
Tsuchinoko - Rarely play.
Turtle - Use the cardboard box a lot.
Water Bear - Have a high survival rate.

Save the game to unlock all music tracks used up to that point. Save the game at the end to unlock all music tracks in the game.

When selecting a character, spin him around for about 10 seconds and he will fall over unconscious.

Place one of your own claymores. Roll into it, then once you have stopped moving have your friend shoot you in the head. Your corpse should go flying into the air.

To make your character hum or whistle, type "SONG" with your virtual keyboard.

To prevent from being locked-on, equip your cardboard box and stay still.

If your character is set on fire equip the cardboard box to extinguish them.

While playing in the Sneaking mode, have Snake avoid lit areas so your shadow will be harder to see.

To make frosty breath disappear, have Snake play dead.

To make you immune to the porno magazine's effect, equip the cardboard box.

Instead of aiming with your weapon, use the camera to look around much faster. Then, when you find a target while using the camera, press Aim.

1. Do not stay scoped for an extended period of time. It allows enemies to easily sneak up from behind.

2. Use claymores and magazines to alert you when an enemy is sneaking up from behind.

3. After making a kill, switch to a different location. Many times, the player you killed will know where you sniped from.

As you play Metal Gear Solid 4: Guns Of The Patriots, you will unlock new songs in Metal Gear Online. All songs will become unlocked with a cleared saved game file from Metal Gear Solid 4: Guns Of The Patriots. Note: Continuing a new game session on that cleared saved game file will cause all Metal Gear Online tracks to become locked again until you pass the point where they are normally unlocked.

Get on a catapult and, when you press TRIANGLE to launch, do not release it while in the air. Your character will do a flying salute.

After obtaining the instructor skill, enable it and do a salute. Your salute changes to a boasting type, where your character puts his or her hands on their hips and pushes their chest out.

When using a USB or Bluetooth headset for voice chat and you want to talk, hold Select to enable voice chat. You will see your name and the corresponding color of the team you are on at the left side of the screen. Hold Select again to disable voice chat.

While playing stages where your breath frosts, have Snake play dead while prone. His frosty breath will no longer be seen by others.

Repeatedly spin your character in circles at the selection screen. When you stop, he will get dizzy and fall over.

Use the colored smoke grenades to alter your character's voice. Throw a smoke grenade and make your character cough by it. The red smoke deepens it and slows it down a bit. The green smoke restores it back to normal. The yellow smoke raises the pitch. White smoke has no affect and will not reset it. This effect does not wear off until you die or a new round starts.