This article covers a group of items without enough details to merit separate articles.
Environmental objects play a large part in helping or hindering players throughout the Metal Gear saga, as well as providing added depth to the scenery of whatever locale Solid Snake, Naked Snake, Raiden, or other characters finds himself in.
Gaps in walls and underneath structures that are just tall enough to accommodate a prone human. Every Metal Gear game features a variety of dead-end or open-ended (see Ventilation Shafts below) crawl spaces suitable for evading the eyes of sentries or gaining access to places unreachable at standing height.
Standard high-voltage security fences can prevent the player from gaining entry into higher-security facilities. The player must either find breaks in the fence that can be crawled through or disable the electric current by shooting out the power source.
When Snake walks in snow or wet areas, or while bleeding, he can leave behind a trail of footprints. If a guard finds these he will follow them to Snake's current position. Crawling is a slow but effective way to avoid leaving footprints in areas where sentries would be sensitive to their presence.
A laser beam or series thereof that blocks entry to particular areas, often rigged with gas, plastic explosives, or some other trap to kill an intruder instantly if triggered. Some games will allow players to disable them by destroying a power source, but the majority require simply passing through undetected. Thermal goggles or Snake's iconic cigarettes are helpful in revealing the beams as they pass, though the latter gradually sap Snake's Life because of their health risks.
An outdoor hazard that traps victims as they struggle to escape. Snake will begin sinking if he steps into a pool of quicksand, going deeper as he moves about in it. Becoming completely submerged or being knocked into the pool results in death.
These often provide good entrances to different areas as they are not patrolled by enemy soldiers. Items are often hidden in them and they can provide good hiding places regardless of the current Alert status.
The main concern with water is that if Snake remains submerged for too long he will drown. The O2 gauge will display for any situation in which Snake's head must remain under water (i.e. a flooded vent). Metal Gear Solid 3: Snake Eater also features a variety of aquatic wildlife that can be caught and eaten for Stamina, as well as leeches that drain Stamina and must be plucked off of Naked Snake via the Survival Viewer.
Fixed machine guns used for point defense by guards - if Snake manages to avoid being cut down by their fully-automatic fire long enough, he can commandeer them to take on large numbers of pursuers at once. Be careful to watch your rear!
Powered guns that are useful for shooting down aircraft and can be hijacked in a similar manner to the Mounted Guns above. Due to their slow turning speed, however, they are much less effective for anti-personnel attacks.
As of Metal Gear Solid 2, Snake/Raiden can use hanging mode. This allows them to swing over railings and dangle from the side, evading the enemies' sight and sometimes providing an alternate route across.
Ladders (or trees, which function in a similar way) can be used by Snake/Raiden to elevate themselves to a higher point. In the case of the latter, Snake can remain at the top, staying out of the enemies sight. This can also be used as a means to cross barriers.
Naturally occurring or man-made (nigh-)bottomless pits. In most cases, anyone who steps on their cover will have a second to avoid the floor dropping out - and in extreme cases can disregard the pit altogether as their running speed far outstrips the pit's opening width.
Some floors creak or clank when someone walks or runs across them, producing heightened levels of noise that can alert enemy soldiers. This can be avoided by crawling, stalking, or by rolling/flipping over them. Without noise reduction methods and equipments such as the Sneaking Suit, moving fast may produce noise even in common terrains.
The most common type of noisy terrain consists of metal grades within floors, some being designed so that footsteps echo when stepped on, even if the person is using noise absorbing boots. Most famous for their presence aboard the dummy tanker USS Discovery. Other examples include wooden floors, singing sand, foliage, and water puddles, the later also leaving footprints.
A door in the floor that leads to a crawlspace underneath. This is a useful way to escape pursuit or stealthily enter a building. Depending on the current game, the player may only be able to exit upwards from trapdoors.
These can usually be unlocked by having the right key, being in an officer uniform or by knowing the radio frequency for the door.
A gimmick from Metal Gear Acid 2. Stepping on oil will cause the character to fall down and become covered in oil. A person in this condition will be unable to see the cards on his hand (as they are also covered with oil) and will ignite when hit by bullets.
Also plays a major role in Metal Gear Solid 2, as an oil spill made the creation of the Big Shell necessary.
Small metallic walls from Metal Gear Acid 2 located in corners that ricochet bullets from some weapons.
In the Zanzibar Land Disturbance, Snake had to wait the wind blow north to safely use the hang glider to pass a crevice, being able to tell its direction by using the smoke from a cigarette. Wind also affects the direction of the gas from gas grenades.
The secret weapon Tanegashima has a chance of creating a strong wind that will blow the target away.
- Drum can
- Electrified floor
- Fire extinguisher
- Infrared sensor
- Surveillance camera
- ^ "Snake, that floor is designed so that your footsteps echo. Listen, Snake. There's a way to walk so that your footsteps won't be heard. I call it stalking. Here's how you do it. First, put your weight on the opposite foot that you're going to step with. Then take a step so that your heel makes contact with the ground first. Then as you slowly lower the tip of your foot to the floor, gradually shift your weight onto that foot. Use your knees to maintain the subtle balance. Try it." - Miller, Metal Gear Solid
- ^ "Watch out for floors that make noise when you walk. Not even those noise-absorbing boots you're wearing can eliminate footstep noise completely. Crawl to move across those types of floors...Over and out." - Roy Campbell, Metal Gear 2: Solid Snake