Metal Gear Solid 2: Sons of Liberty

Versions

MGS2 has gameplay differences between every version of the game. The main revisions (in order of release):

• Sons of Liberty (US)
• Sons of Liberty (Jp): Dog Tag changes, most notably some Marines in Tanker Holds. Boss Survival/Casting Theatre modes. Various bug fixes and presentation changes. This version only: V.Easy, Easy, Normal and Hard are named Easy, Normal, Hard and V.Hard respectively.
• Sons of Liberty (Eu): European Extreme difficulty. C4 locations changed in Strut D and Strut A Deep Sea Dock.
• Substance (World): Exploits and glitches fixed, most notably the Tengus Coolant glitches (made significantly more difficult to execute) and Elevator floor clip. Extended Boss Survival mode. Snake Tales, Missions, and (PS2-only) Skateboarding modes. Various bug fixes.

While PAL (Eu) and NTSC (US, Jp) ostensibly run at the same speed (adjusted to compensate for PAL's lower frame rate), there are various subtle differences in PAL versions either caused by it, or specifically added for other reasons:

• Many guard and mech routes are slower, which can make things easier or harder depending on the situation. This (and other timing effects) are caused by routes using a frame timer (instead of a real-time timer) which has not been compensated for.
• Elevators (including the one in Strut A Deep Sea Dock) take longer to appear.
• Button actions take longer to take effect, including firing (which makes it difficult to fire a pistol rapidly), opening equip menus (which also gives Quick Equip a bigger window) and equip scrolling.
• First-person aiming is slower, as the distance covered when adjusting it is measured by the frame.
• Codec conversations, when skipped with Square, take longer to do so (one screen per frame).
• There is less slowdown in graphically-complex areas such as outside on the Tanker, the Holds, Fortune and Rays. Game time is measured in frames, so slowdown (or the lack of it) does not give one version an advantage in game time. However...
• Fortune's attack patterns are changed to compensate (or rather, over-compensate) for the huge slowdown in the NTSC version. PAL Fortune attacks 16 more times on Extreme.
• Fatman's loop strategy only works on PAL versions. When attempting it on NTSC versions, after you trip him twice, he gets up and runs away, no matter your location.

There is also a difference caused by translation that affects all languages. Some guard actions (such as initiating Alert/Caution) are timed to take effect once they finish using the radio. Depending on the dub, some languages will take longer than others, and so some marginal hit and run strategies may not work.

Categories

Metal Gear Solid 2 runs should be classified by version (including region) and difficulty/end-game ranking. Possible main categories for runs include a mixture of the following:

• Big Boss code name/Any code name
• All dog tags/Any%
• No damage/Damage taken to save time
• Single-segment/Multi-segment (Big Boss may use 9 segments)
• Extreme/European Extreme difficulty
• [Not] Game Over on Discovery
• Sons of Liberty/Substance

Weapons

• Quick reload

Double-click R2 to refill your clip quickly. You can also use this to skip the end of a long firing animation (e.g. the M9, which needs a round loaded for every shot), which enables you to shoot at a faster rate. For example, if done fast enough, you can run at a guard and send them to sleep in three shots (Ex/EuEx) before they can turn around.

You receive a magazine when you run out of bullets in a clip - using quick reload stops this from happening.

• Lock-on headshots

Pressing L1 while aiming with a basic gun (M9, USP/SOCOM, M4/AK) while near an enemy (not bosses in Ex/EuEx) switches your aim to their chest. You can use this to run and shoot by holding L1, but it also simplifies aiming for headshots.

Hold Sq and R1 to aim in first person, then tap L1 to aim at the chest. Then move the aim up to the head and fire. With practice this becomes easy and quick.

• Quick equip modes

There are two quick equip modes in the Options menu - they affect what happens when you tap L2 or R2 instead of holding it. Unequip mode unequips the current item if it is equipped, and equips the last-equipped item if there is nothing equipped. This is the same behaviour as L1 and R1 in MGS1. Previous mode acts like Unequip mode if you have only equipped one item since you last had nothing equipped. Otherwise, it will switch to the last item you had equipped, meaning it will switch back-and-forth between two items repeatedly.

Unequip is the default mode. It is most useful when you expect to use a variety of items or to grab enemies without a weapon. It's also the easiest mode to use, and in general it won't do anything you don't expect it to.

Previous mode is significantly quicker, and more intuitive, than Unequip when you expect to use two items only, or when you will repeatedly switch between two. In the Tanker, where the only weapons you're likely to use are the M9 and USP, Previous is king - once you've equipped the USP, you probably won't need to enter the weapon menu again. However, in the Plant, if your second weapon is first-person - Stinger, PSG-1(T) or Coolant - techniques like quick reload will make you stop running for a short time. You can deal with this by quick-reloading during a cartwheel.

Enemies

• Lengths of stun/tranq

The period of time an enemy will remain knocked out is dependent on difficulty setting. M9 tranquilizer rounds will knock an enemy out for 9 minutes on Very Easy and Easy, 5 minutes on Normal, 3 minutes on Hard and Extreme, and 40 seconds on European Extreme. A stunned enemy (with stars around their head) will remain stunned for 1 minute on Very Easy and Easy, and 30 seconds on all other settings. The time enemies remain down continues to pass when outside of the room; this is incorporated into the current E-Extreme strategy for bomb disposal in Strut E, where tranquilizing the guard patrolling the right-hand staircase last before leaving gives enough just time for the player to defuse the heliport bomb and return without them waking up.

• Sight and sound

The enemy's field of vision is relatively narrow, and does not change between difficulty settings. The distance from which an enemy becomes suspicious of the player, and the distance at which they discover the player, however, change significantly. See the image on the right for distances scaled to the in-game radar. Note that on European Extreme, an enemy can become suspicious of the player from a distance beyond that of the radar. The distance enemies can hear wall knocking is equal to the distance at which, in a straight line, they would discover the player. Certain enemies such as binocular-using guards, for obvious reasons, do not adhere to the same sight distances as standard enemies. Interestingly, at least two standard guards - the left-side guard in the second room of Deck-A, and the guard on the balcony of the Aft. Deck in the tanker chapter on the European Extreme setting - have lowered sight distances than the difficulty would demand (both remain at Hard/Extreme). This is (presumably) because Snake comes into both guards' distance of sight during in-game cutscenes, and would be discovered with European Extreme sight. Supporting this idea, their ability to hear is unaffected.

• Knock-down tranquilize

If you shoot an enemy with a tranq dart (M9, PSG1-T) anywhere, they will fall asleep as soon as they are knocked down. Any technique will do; combo, roll, throw or grab/strangle.

• Tranq an enemy looking in your direction without stopping

When running at an enemy that is looking in your direction, wait for them to see you, then shoot them once with a USP/SOCOM/M4/AK round shortly before they fire. This normally gives you enough time to approach them, shoot them with the M9, and knock them over. If not, you can shoot them again before they finish recovering.

This only works if you selected Not Game Over If Discovered, and depending on the situation it may alert other guards.

• Daze

Shoot an enemy's blue "!"-sign and they will stand in a daze for 10 seconds (or until you attack them). The easiest way to do this is to stand a certain distance away in front of them and wait for them to walk towards you and notice you.

It is possible (though difficult) to shoot them once in a nonlethal location (lethal: head, crotch, heart), then shoot the "!" that appears quickly.

• Hold up with any weapon

Any weapon can be used to hold up an enemy. Hold Sq lightly with the M4, AK, Nikita and RGB6. Simply equip the Stinger, PSG1 and PSG1-T while looking at the enemy to hold them up.

• Scare without firing

Normally you would scare a held-up enemy by shooting them with a lethal weapon in a nonlethal area (or by shooting near them, which is faster). You can also scare them by equipping the Stinger and looking at them, or by aiming the RGB6 or Nikita at them. This can be useful if you don't have a suppressed pistol or rifle but do have one of the above weapons.

• Coolant attack

The coolant, while it has a short range, also affects a large area in front of you. It stuns an enemy for about three seconds, and can be used in stealth (the enemy acts as though they have been shot by an unseen enemy) or in battle (it affects all enemies in front of you so it is an effective close-range crowd control weapon).

Movement

• Coolant rise

While crawling, with the coolant equipped, press X to rise and immediately press R2 to unequip the coolant. You will immediately be in a standing position. The timing is quite lenient; you can press both buttons at the same time.

The trick can be used in general play (e.g. Strut A during the bomb run) when you have no weapon equipped and the coolant is your last-equipped weapon (Unequip mode), or when it is your previous weapon (Previous mode). Crawl as normal, then, when you are able to rise, tap R2 and immediately tap R2 and X together. Depending on your speed, this can be up to a second quicker than rising normally.

• Travelling with a box

Walking with a box equipped has three uses that I know of:

1. You have a smaller turning circle, so you can turn 180 degrees in place while running. This makes Fortune significantly easier on Ex/EuEx.
2. Your height is halved, making it useful in areas with low cover such as Strut E. It also travels underneath the projectors in Hold 1 and Hold 2.
3. It slightly increases the size of your hitbox for setting off claymore mines, but your hitbox for being hurt by them remains the same. This means that it's possible to set off a mine but not actually be hit by them (e.g. Strut A roof after Fortune - dodging the claymore is possible without the box, but is easier with it).

• Roll/cartwheel tricks

1. You can roll up or down about 4 steps of stairs with Snake.
2. You can cartwheel down stairs with Raiden significantly faster than running.
3. Raiden can cross gaps (e.g. Shell 1-2 Connecting Bridge after Harrier) with his cartwheel.
4. Roll/cartwheel is about the same speed as running, but it is faster at first and slower at the end. In some situations you can cartwheel into an enemy's line of sight so they see you earlier, and (e.g. Raiden Sneaking 2) notice you rather than alert. In others you can use it to reach the side of an enemy as they turn towards you (e.g. Raiden Sneaking 5).
5. Use roll/cartwheel to travel forward in situations where the game would normally force you to stop (e.g. Strut D-E Connecting Bridge when called by Deepthroat). You can also use it as a buffer to equip a new item/weapon without stopping.

• Running up and down stairs

In the PS Vita version of the game, holding the weapon holster button (D-Pad down) while moving will have the player character maintain their current pace and bearing. When running towards stairs, hold the button to run directly up (and down - only really useful as Snake) them without stopping. This may work in the Xbox/360 versions of the game, given the similar control method.

Misc

• Quick bomb freeze

If you are at an angle (e.g. facing near the side of the bomb), the coolant will sometimes affect more than one point on it, and freeze it in half the time.

• Quick elevator summon

The elevator trick from MGS1 is also in MGS2, but isn't quite as quick. Press the button to summon the elevator twice, and the doors will open about two seconds later.

If you're unlucky, this can be slower than normal play - occasionally the doors will open immediately the first time you press the button.

• Answer codec calls manually

Some mandatory (the icon appears red rather than blue) codec calls force you to stop. You can answer the call immediately with Select and save about a second.

This can also give you a head start in some areas (e.g. in Arsenal Gear as X-Raiden, if you answer Campbell at the start immediately, you can run along the south wall and change the first Tengu from what would normally be an Alert, to a notice).

• Skip some codec calls and cutscenes

You can avoid Rose's codec calls that usually appear on the first time through Strut F-E Connecting Bridge and Shell 1 Core 1F by being in Caution status when you enter these areas. This also works in the Engine Room to stop the door repair guard appearing.

• Avoiding the Stinger

While not a timesaver, if the player defeats the Harrier without the Stinger, it will appear fully loaded in their inventory regardless at the beginning of the Metal Gear RAY fight, which is impossible without either the Stinger, or RGB6 (with more ammo than it can hold required).

Big Boss

Big Boss is the top rank on Extreme and European Extreme. The requirements are:

• Tanker-Plant
• Time under 3:00:01
• 8 or less Saves (PRUD ENCE)
• 3 Alerts (ALRTNUM)
• No Kills (NUET)
• No Rations used
• No Continues
• Damage taken under 11 life bars minus 50 (DMGA MMOUNT)
  • This is 10 life bars on Extreme, or 9.3… on Euro Extreme
• Shots Fired under 701 (AMMOUS ED)
• No Special Item (Wigs/Bandana/Stealth) usage
• No Radar

Notes:

• The names in parentheses above refer to the stats shown on Plant's Mission Failed screen. You can die after saving to examine your current stats in a segmented run.
• Mission Failed (or rather, Fission Mailed) also appears twice during Tengus 2. The stats shown here are accurate - if ALRTNUM is 3 at this point, your Alerts stat is good.
• The "damage taken" requirement is dependent on difficulty. One life bar is 200 (Very Easy)/120 (Easy)/100 (Normal)/75 (Hard)/50 (Extreme)/30 (Euro Extreme), so damage taken ranges from 10.75 bars (on VE) to 9.3… bars (on EuEx).
• 700 shots is plenty. You're only likely to fail this if you waste ammo in an area with ammo spawns (most likely the oil fence sniping area).
• The three mandatory Alerts occur at the start of the oil fence sniping area, the start of Tengus 1, and the start of Tengus 2. You're not allowed any unnecessary Alerts. Note that continuing from Game Over in any of these three areas will add to the alert count (even though continues will void the rank regardless).
• These requirements also apply to the other difficulties (except for Very Easy) for their top rank.
  • If you slightly miss the top rank for a higher difficulty, the ranks for all lower difficulties are also available with slightly easier requirements. This means that four upper ranks are available on Extreme, but only one on Easy.

Strategy:

• If you do something to fail a requirement - for example, killing someone, or getting an Alert - save your game before leaving the current area. When you reload this save, your stats will be the same as they were when you entered the area. Of course, you can only do this a maximum of eight times.

Difficulty Differences:

• Unlike Metal Gear Solid 3, the core gameplay of MGS2 changes between Extreme and European Extreme difficulty.

1. Health is reduced from 50 to 30 hit points. Regenerative health is reduced from 16-17 to 10-11 (HP is restored in 2s when crouching so the possible maximum can change)
2. Enemies do not carry any items
3. Rations are completely removed from the game (getting sea lice in the inventory reveals that, theoretically, the Extreme limit of 2 rations is still in the engine)
4. Enemies see and hear significantly farther
5. Enemies tranquilized with the M9 wake up after 40 seconds as opposed to 3 minutes
6. Enemies take slightly longer to tranquilize (without hitting critical areas). The difference is minimal though - no more than a second
7. Enemies take longer to stun - 25 singular punches instead of 20
8. Enemies take longer to kill - 10 spaced gunshots at a guard's chest (avoiding the instant-kill heart hitbox) versus 6
9. The button mashing sequence with Solidus is significantly harder on the initial console versions (55-65 seconds, region dependent, as opposed to ~30). The HD collection version drains oxygen faster, but lasts a measly 14 seconds by comparison.