Derail

Derail is a multiplayer map featured in Call of Duty: Modern Warfare 2. This large map takes place around the site of a train derailment (hence the name) surrounded by a forest, in what is presumably Northern Russia. The map is covered in a thick layer of snow. There are several buildings for players to fight amongst as well as train cars which provide additional cover. There is also a vast "field" that has basically no cover to hide behind, along with several paths around the yard.

Derail is often considered a sniper-orientated map, though it can easily accommodate many different styles of play.

Fighting is generally centered around the two buildings on the far side of the map, on the opposite side of the two buildings with ladders attached. The smaller building is the more popular, due to an over-looking view of a large, empty field that is easy to shoot into and the fact that it has only two entrances. The other building is much larger, allowing snipers a good view to the opposite building, though it is hard to defend. The main fight takes place around the area where the train derailed (hence the name). Arctic ghillie snipers are invisible from afar and prove a dangerous threat if hiding in the snow. The most overlooked area of the map are the the either sides that are filled with white foliage and mounds of snow. Derail is a map of silence and limited gunfire where one shot (and a silencer) can mean life or death. Quick, powerful, and accurate shots are extremely important here. Running out into the open without caution and camouflage can easily end your life. Consider taking one designated marksman and one sniper in a squad or consider having a team of long range riflemen.

Tactics

 * A common strategy is to camp in the center building with One Man Army and continuously plant claymores on both entrances. This is made much easier if teammates help hold down the building. Another way of doing this is to use Scavenger instead of One Man Army to help continuously resupply on the number of claymores. A good player with an assault rifle and a shotgun can easily hold down the building single-handedly using this method.


 * The trees on either side of the map provide excellent cover for flanking. It should also be noted that the bushes make the player nearly invisible to the enemy.
 * Many enemies camp inside the large warehouse near B in the middle of the map. A good strategy is to flank around the building, giving it a wide berth, so as not to attract attention. Then, Enter from the small darkened room. Check the right corner of the room for enemies. Then, throw a stun/flash off of the wall near the staircase, so as to hit any enemies in the room above and disable claymores. Then, check the next room with caution. As the player approaches the main room, hug the right side of the middle room and bounce a stun/flash off of the doorway. If unsure about the amount of enemies, throw in a frag/semtex as a backup. As soon as the grenade blows, storm the room and eliminate the enemies.

Miscellaneous

 * This map provides several high vantage points ideal for placing Sentry Guns. This includes the parapet out of the warehouse in the back, looking out of the windows in the central building (provided your team controls it), on top of one of the rail cars, or on top of one of the single story buildings near the Task Force 141 start.


 * In the central warehouse, one can crouch and camp at the base of either of the staircases leading up to the second floor. This, although frowned upon, allows for quick and easy kills. Using Claymores and Scavenger increases the effectiveness of this tactic.


 * Whenever assaulting the warehouse, throw flashbangs and stun grenades into the stairwell to blind the campers who might be hiding there.


 * On this map, the AC-130 circles around the map but leaves some areas where the weapons cannot aim to. Use this to great advantage to quickly take out any enemy AC130s that are called in. The best way to take down an AC-130 or Chopper Gunners is to have the Cold-blooded perk and fire a Stinger from one of the windows of either warehouse (the player will be very hard to see indoors), then quickly relocate to another window as the gunner will see the smoke trail and fire again. In the case of AC-130s, however, there may need more than one person with Stingers, a Javelin or the Scavenger perk.
 * A smoked doorway can conceal a claymore accidentally placed in the middle.


 * Because of the vast distance that players are placed from the opposing team's spawn, it is recommended to have Marathon or Lightweight perks to reach the enemy quickly. One can also use the Marathon and Lightweight combo to flank the enemy quickly at the start of the match.


 * Due to the many blind corners this map has (under the bridge, inside the buildings, at the power generator etc.) tactical knife or marathon/shotgun classes can be extremely effective. In addition, if the map is known fairly well, there are many places for a person to jump down snowbanks or from buildings to kill someone as one of the aforementioned classes.


 * Within the ground floor of the railyard warehouse, there are stacks of boxes which provide well-covered vantage points for camping objective B (for Search and Destroy and Demolition) and also make an easy job of camping the main entrance of the warehouse.


 * Most players don't realize that you can go inside the multi-story buildings in the back of the town. There are plenty of covered areas within them that provide shelter for players who want to use their killstreaks or finish the Survivalist Challenge. It is also a good place to plant a Tactical Insertion on Capture the Flag if the enemy flag is by the TF141 spawn point (for Team Deathmatch).
 * Because some of the train cars are open, you can run and jump up in the cars to use user-activated kill streaks.
 * You can get on top of most of the train cars using the ladders along the sides of them. This is also possible on the engine on the western edge of the map.
 * The best place to guard flag " A" in domination is to camp in the strip mall across from the gas station.

Stealth

 * It is suggested that players using the Arctic Ghillie  suit not snipe from inside the many platforms or buildings, or from the train cars. The ghillie is intended for use in the snow; its white colour stands out considerably against the dark interior of nearby buildings.
 * Using any colorful camouflage makes your weapon extremely visible against the snow.
 * The back houses and the parts of the map that are not played can be a good place to complete the Survivalist Challenge. Use Cold-Blooded Pro and Ninja to hide and hopefully nobody will find you.
 * A player with Scrambler and a Heartbeat sensor can stand near the main warehouse and inform their teammates of the enemy's location, while the enemy will be trying to find the jammer exposing their hiding spots and teammates can catch them off guard.

Sniping

 * The Thermal Scope is very ineffective because they will appear slightly brighter than the snow, however a sniper with Cold-Blooded will stand out against the snow.
 * The Heartbeat Sensor or Claymore is suggested for snipers taking cover within the warehouse.
 * A decent spot for snipers would be overlooking the big snowy field on either side. The players in the field have very little cover and stand out in contrast to the white snow.
 * Contrary to popular belief, the raised bushy patch on the eastern side of the middle building is a bad shooting position; many snipers and sharpshooters get picked off by players near the generators to the south-west thinking they were hidden by the foliage. The exception to this is in HC HQ where if the HQ spawns beneath the bridge a silenced sniper rifle can pick off any enemy trying to take the HQ and the lack of killcams prevents the player being noticed. However any experienced player will expect this and quickly dispatch the player with a lightweight class.
 * Typically, there will be a Spetsnaz sniper on the bridge over the train, you can shoot through the thin metal with FMJ, awarding you with yet another step towards Extended Mags.
 * The single-story brick structures in the town area provide extremely good vantage points for snipers. The snow covered roofs make it easy to miss a stationary sniper wearing an arctic ghillie suit and the ventilation duct on the northernmost building is high enough to see out under, making the shooter all but invisible until they fire. Best of all, any player can sprint fast enough to leap from one building to the next, making covering both flanks a breeze. Finally, guarding yourself from sneaky, vengeful players is extremely easy since both structures' rooftops are only accessible via two ladders apiece which are easily checked and/or claymored.
 * Despite the massive distance between spawns on this map, it is very easy for the defense team to wipe out the attackers before they even reach them. To cover the bridge side, a sniper with Marathon can run all the way to the third floor of the back warehouse and bust the windows to access a snowy parapet that offers a perfect and shady spot to pick off attackers before they cross the bridge or run past it towards the northern flank. The southern approach is also easily defensible. The best method is to climb the snow-covered boxes next to the cargo containers near the central office structure. From the top of the container, one can then jump back to the highest box and from there jump left to another container which overlooks the entire southern flank, and the fence provides decent concealment with some fine adjustment of position. This particular spot is also out of line of sight from the infamous town rooftops which usually allow the attackers an early advantage. Having two skilled snipers to use these two spots forces the enemy to approach the railyard directly, which is an extremely uncomfortable position.
 * The snowy ledge outside the windows of the the third floor of the railyard warehouse is an excellent spot for concealment and distance, but has a weak point. If a sniper enters the train car right before the bridge on the town side, they can get a good view of that spot from on top of the boxes in the back of the car. Also on the second level and third level are sets of windows that enemy snipers can take clean shots of you going up the levels.
 * Avoid Cold-Blooded on this map, especially if you are sniping in the snow and enemy snipers are using thermal sights.
 * If you go to the highest floor on the North warehouse and go through the window on to the roof, you can jump off to the left (if facing south) and land on the protruding ventilation pipes a level below. This spot gives a good view of the West section of the trainyard, but you are very vulnerable to any good sniper.
 * The bridge that goes over the train is a good ally-way shot, due to less cover.
 * Use the top floor of the warehouse, which has a good view of the gas station where people snipe. In addition, this gives a view of the "A" flag on domination, which means a sniper can kill people attempting to capture it.
 * On the second floor of the warehouse, windows are good sniping positions because nobody uses them, and therefore they are often not checked by enemy players. The windows above the containers also have a view of people who climb up the ladder in the front by the wooden fence.
 * One Good place to snipe from is at he back of the map where the brick buildings are next to the last rail car there is a wooden building. If a sniper climbs up the rail car and jumps onto the ledge of that building they will be able to snipe from that location. Lots and lots of enemy players run right in front on their way to climb up on the gas station or the adjacent brick building. Most times you can snipe these players on the rooftops very easily.
 * Another great place to snipe from is the rail car forward of the one that has the vehicle and generator on it. A sniper can climb up on the car and go prone and then he will have a great view of almost the whole map without being seen. The only drawback is if the enemy climbs up on the brick building next to the train. After the sniper get 2 or 3 kills he can move to the location mentioned above.

Trivia

 * Some of the locomotives have the number 1337 on them, commonly known as l33t or leet it also stands for Elite. These same markings can be found on the Call of Duty 4 map Backlot.
 * On the flatbed car of the derailed train there is a part of a satellite that is seen in the hangar during the mission "Cliffhanger." It is possible that the premise for this map is a TF141 sabotage mission on the Russian train.
 * Also, several of the train cars and containers have the words "Kriegler" (Lead Map Designer) on them making reference to the name that is seen on many levels including "Highrise", "Suspension", "Crew Expendable", and "Mile High Club".
 * Some of the trains have the letters "IW" and a few numbers referring to Infinity Ward.
 * There is a teddy bear in the central building in a file cabinet, it can be opened by hitting it.
 * This is one of the only multiplayer maps the old game "Border Patrol" can be ressurected, a private match game that originated in Call of Duty 4.
 * One might presume that since the snow is cold, it would appear black and lead to the thermal scope being extremely effective. However, this is not the case, as a thermal scope detects specific bands of radiation, sunlight reflecting from snow would cause it to appear grey on a military issue scope. However in game as the scope is not a true thermal one snow appears white hot.
 * The box car that is in the ice can be accessed by getting under the map in spectator mode. Inside is nothing but darkness and a little bit of snow.
 * The box car on the bridge is the exact same thing as the above quote. It can serve as a good camping site for people with cold blooded pro and/or ninja.


 * In one of the garbage cans in the main office, there is a sticker of Santa.
 * The power line towers can be heard creaking in the wind.
 * This is one of the more common maps to use an elevator on, due to the flood of YouTube guides
 * The yellow engine near the Spetsnaz spawn is not on the train tracks, which is strange but could be an oversight.


 * Weapons, when viewed through first-person, appear to have frosted over. This is easiest seen with Urban or Red Tiger camouflage. On guns where the camouflage cover most of the gun and are metalic, appear to have Blue Tiger on them even though no camouflage is applied. This is most noticable on the AK-47.
 * The gas station in the small town is called "Nova" which is an English word which is odd as the map is presumed to be in Russia, although this could be an error by Infinity Ward.

Glitches
There is a glitch which allows the player to reach the big hills outside of the map, next to the warehouses of the edge of the map, the hills provide great cover and sight, it is a deadly sniping point, but note that this is considered a "cheap shot"