Fallout 3 traps

Traps in Fallout 3 can be found all over the Capital Wasteland.

Cars and motorcycles
These are highly explosive decaying vehicles lying around almost everywhere in the Capital Wasteland. They catch fire after they take a sufficient amount damage and slowly deteriorate before exploding. The explosion is similar to that of a mini nuke because of the flash of light, mushroom cloud, high amount of damage inflicted, and the radiation left over that disperses over time. They are extremely dangerous and can easily result in death at close range. Any other vehicles in direct contact with an exploding one will immediately explode as well, while nearby vehicles will be set on fire which should give you time to get far enough away before they explode (the delay depends on the amount of damage the vehicle receives). During the quest Traversing a Mine Field from the first chapter of the Wasteland Survival Guide, you'll find yourself under sniper fire from Arkansas, who deliberately detonates the cars from a distance. The explosions do more damage than the mines and avoiding them would be best if you plan on making it to the playground alive. Just for reference, cars cannot be disarmed or rearmed at any time.

Mine
A common explosive that is set off by getting close to it (proximity fuse). Requires Explosives skill of 1 to disarm. They can be picked up after being disarmed. Mines can be set off by followers. The higher your Explosives, the longer the fuse will last, and the longer you'll have to disarm it.

Bear trap
Requires Repair skill of 25 to disarm. A bear trap snaps shut on the player's leg and can cripple a limb. Triggered by walking on the trap or an object landing on the trap. Bear traps can be reset which requires repair skill of 55.

Swing object
Requires Repair skill of 25 to disarm. An object (often a girder, automotive engine, or rotting Brahmin body parts) that swings down and hurts anyone who it hits. Set off by trip wire. Note: this trap can hurt you more than once if you walk into the object or stand in one spot with the object on a angle touching you. Can be disarmed by tripwire or by grabbing and moving it down. Note that even when disarmed, running into the object can cause damage. Also can cause damage when manually moved by the grab action.

Grenade bouquet
Requires Explosives skill of 30 to disarm. A cluster of three frag grenades hanging from a string. Once you walk into it, its trip wire has been set off, or shot, the grenades will be released and will detonate after several seconds. Can be disarmed independently of its trigger. Disarming this trap will give your character three Frag Grenades.

Pitching machine
Requires Repair skill of 35 to disarm. A pre-war pitching machine that is rigged to shoot baseballs that cause damage. It is usually more of a warning for enemies though, as when it goes off, they become suspicious. Set off by a pressure plate or a trip wire. An excellent example of this trap can be found in the Arlington Public Library.

Gas leak
A gas leak is a very dangerous trap in case of combat. Shooting while you're in the gas cloud yourself will ignite the gas to a fireball. If you're on fire too, you'll be knocked out of combat for around 5 seconds. Pinkerton uses the gas in combination with the rigged shotgun: On the moment you'll walk through the tripwire, the shotgun goes off and the gas will ignite. Note that with throwing a grenade the gas will ignite too and enemies will be hurt severely. Energy weapons, such as the laser pistol, can also be used to set off a gas leak from a safe distance. Warning: If you are currently wielding a Flamer, Heavy Incinerator, Slo-Burn Flamer or Shishkebab, the gas will ignite the moment you step into it. This is because the tip of these weapons are constantly on fire when ready for use.

Radiation trap
Added with Broken Steel add-on, releases radiation upon activation and requires Repair skill of 60 to disarm. However, they only exist in two locations. In Holy Light Monastery they can only be activated manually, while in Olney Powerworks they are initially active and must be shut down using a nearby terminal.

Rigged Shotgun
Requires Repair skill of 45 to disarm. A Combat Shotgun that is rigged to shoot whatever sets off its trigger, either a pressure plate or trip wire. Can be disarmed independently of its associated triggers. Disarming this trap will give your character a Combat Shotgun, 4 Shotgun Shells and 10 Microfusion Cells(the Microfusion Cells are the power supply for a winch or powered fishing line spool that pulls the shotguns trigger)

Rigged baby carriage
Requires Explosives skill of 60 to disarm. An explosive trap that consists of a Baby Carriage containing a toy baby with a bomb and several frag mines strapped to it. Upon approaching the carriage, the toy will emit a crying sound and then the whole thing will explode, causing some hefty damage and a scary moment. Once disarmed, it can be rearmed as a time bomb, or a proximity bomb. An example of this trap can be found in the Meresti Service Tunnel.

Rigged mailbox
Requires Explosives skill of 60 to disarm. A mailbox that is rigged with explosives to explode on proximity and can be rearmed on either a time or proximity detonator. Nearly identical to the rigged baby carriage in interactivity.

Rigged terminal
Requires Explosives skill of 45 to disarm. A computer terminal rigged with a Frag Grenade. The attempt to use the terminal triggers the trap causing slight electrical shock and shortly afterward the detonation of the main charge. The trap can be deactivated by defusing the back panel. Disarming the trap will give the Frag Grenade. An example of this trap can be found in the drainage chamber near Jocko's Pop & Gas Stop (the source of Signal Sierra Victor) or near the entrance to Pinkerton's hideout in Rivet City. Note that the terminal can NOT be used for informational purposes, either before or after the trap activates; it is only possible to re-arm it with a different grenade.

Toilet trap
Tenleytown/Friendship Station's bathroom nearest the Chevy Chase North exit contains a toilet that will harm the player if used to regain health, upon further inspection of the bog, the player should notice two wires coming out of the bowl and into the tank (where the flusher is) apparently connected to several Microfusion Cells, the player can disarm the trap and get the cells. The player could have been warned about this trap by the skeleton on the floor holding the rim of the toilet. Another one can be found in the Robot Repair Center.

Tripwire
A wire that is tied to two posts. This trip is very hard to see in combat. Can be avoided by having the Light Step perk. Requires Repair skill of 25 to disarm. You can disarm it by looking at one of the posts and activating it.

Pressure plate
A pressure plate is set off when it senses pressure from the PC stepping on it, thus triggering the trap. A common way to avoid setting off bear traps and pressure plates is by having the Light Step perk. Requires Repair skill of 25 to disarm. Bear trap can be quickly disarmed with a direct gunshot.

Movement
All mines including the Carriage Trap are triggered by getting close to them (proximity fuse). Can be avoided by having the Light Step perk. To disarm, slowly creep up to the trap. If you hear a beeping, either try to run away, or better, pick up the pace to the trap and quickly disarm it.

Usage
Rigged equipment such as computer terminals may be triggered by attempt to use.

Remote detonator
The Preacher in Seward Square apparently sets off his minefield remotely. Also, similar to remote detonation is using a sniper rifle to shoot the trap from a distance.

Video
YouTube video about House of Traps in Fallout 3:
 * http://www.youtube.com/watch?v=VHo8JJKMmVs