Epsilon Armored Railgun

The Epsilon Armored Railgun is a vehicle that the Air Raider can call on in Earth Defense Force 2025' and Earth Defense Force 4.1: The Shadow of New Despair. It also appears in Earth Defense Force 5 where it is called the Epsilon Self-Propelled Railgun''' and is instead exclusive to the Ranger.

Description
The Epsilon is a heavy tank, slower than a near-level E551 Gigantus and with slower turret rotation as well, but heavier armor. It is a 3-seat vehicle armed with a powerful electromagnetic cannon operated by the driver, and two heavy machine guns on either side. The machine guns are entered from the sides of the vehicle and have a fire arc of slightly greater than 180 degrees on the side they are on, while the driver enters to the rear of the vehicle. The two machine guns are mounted on the turret and rotate with it.

With the exception of the 4D Burst model, all Epsilons fire a single powerful projectile with a perfectly flat trajectory; the projectile is around the same speed as a Ranger's sniper rifle bullets, and still requires some target-leading at a distance. The 4D Burst instead fires a fairly tight spread of 4 projectiles.

The projectiles fired by the Epsilon's main gun will penetrate multiple targets, and unusually for non-explosive weapons they can also destroy buildings. A shot from an Epsilon cannot penetrate an intact building, however; a projectile that hits a building will be destroyed.

In 2025 and 4.1 the gun sadly lacks a collision box, so any plans to use it as an impromptu ladder will end in failure.

Earth Defense Force 5 also includes the vehicle, now sporting a fetching blue paintjob. The damage of the vehicle's railgun has been reduced by at least one-third for all variants, but it otherwise handles identically. The gun now has a collision box and so the Epsilon has additional firetruck-ladder functions.

Strategy
Being effectively a tank-sized sniper rifle, the Epsilon is most effective against single targets such as boss insects, Hectors, Deroys and Carriers. The main gun has no splash damage and can only damage multiple enemies if they are lined up. It does have a limited ability to handle crowds with its machine guns, but these are nothing like as strong as the revolver cannons of a BM03 Vegalta and the Railgun will quickly be overwhelmed if it is faced with a large swarm and not supported by either ZE-Guns or other players. The machine guns have a broad cone of fire and have momentum added to their aiming, making them a little clumsy for precise shooting and more suited to "spray and pray" fire. Aiming the machine guns becomes faster and more precise the higher the Epsilon's level becomes: with the final model, the momentum effect is completely removed.

The Epsilon's turret moves relatively slowly and it is best to turn the entire vehicle to roughly aim and then use the turret for fine aim. The main gun has a laser sight for fine aim (one of only two weapons to have one in the original EDF 2025, the other being the EF31 Nereid's Auto-Acquisition Autocannon), allowing shots to be placed accurately at long range; this is a must given its limited ammunition and fairly long pause between shots.

While the E651 Titan is much tougher, has higher damage for its main gun and much better secondary armament, the Epsilon is faster, much easier to aim effectively and requires two-fifths of the supply credits of its larger cousin, making it much easier to keep in the fight.



As with most Air Raider vehicles there is a limit to how high the main gun can elevate, which can make hitting targets like high-flying Carriers, Earth Eater core modules and the Quadruped Fortress' transport bay difficult. It is possible to increase the elevation of the gun by parking the Epsilon on a slope or placing it half-on a pile of rubble or other suitable object to hit such targets.

Like most armored vehicles, it is very easy to jump on top of an Epsilon and the long, flat nose makes a great location for placing turrets, which can grant better emergency protection than its secondary weapons. It should be noted, however, that while the Epsilon's main gun does not have a collision box, it does have a hitbox, and it is often necessary to elevate the gun to stop turrets from hitting it instead of what they are trying to shoot at. As with other vehicles, playing ZE-Launchers on an Epsilon is only really a good idea if it urgently needs to be destroyed for some reason. The rear is better for placing power / guard posts or forcefield generators, since at the front they will make the weapon harder to aim.

EDF 2025/4.1 Variants
All Epsilons have a crew capacity of 3 and reload for 3,000 credits.

EDF 5 variants
The reload credit requirement for an Epsilon varies as with most vehicles depending on upgrade level: in its case, even the minimum number is highly variable.

Trivia

 * The Epsilon's hull front appears to be based on that of the American M48 Patton tank, while the rear resembles the Israeli Merkava or Swedish CV90, with the turret somewhat resembling that of a Stryker Mobile Gun System. The turret itself is an oscillating configuration like the French AMX-13 (which the turret also resembles), a configuration where the turret consists of two parts one of which moves relative to the other to provide elevation, normally used to mount an outsized gun on a light chassis. Presumably the curved structure at the rear of the gun is a double-sided magazine for the weapon's autoloader.
 * The overall look of the vehicle is also very reminiscent of the YMT-05 Hildolfr tank from the Gundam universe.


 * Due to its sloping hull front the Epsilon is particularly prone to being hurled ridiculous distances by certain physics events, such as if it is stepped on by a Hector. This can be seen here.
 * The Epsilon has purple optics and glowy bits in 2025. These are changed to red in 4.1.
 * NPC Epsilons added in 4.1 have infinite ammo, making them exceptionally useful allies. Since they do not turn their hulls, their cannons track much more quickly than any player-accessible Epsilon, even able to keep pace with Dragons. As with Titans they do not use their secondary weapons, meaning defending them is important if the player wishes to benefit from their powerful supporting fire.