Fourth Armor

The Force Armor (フォースアーマー), mistranslated as "Fourth Armor" outside of Japan, is an all-around armor first found in Mega Man X4. In its debut game, it was collected in four parts and slowly became more powerful as the parts were collected, similar to armors found in the previous games.

A reconstruction of this armor created by Alia can also be obtained in Mega Man X5. If X is chosen at the Character Select screen at the start of a new game, he will begin the game with the armor equipped. The second Arm Capsule ability is in effect, enabling the Plasma Shot, but the effects of the Helmet Part are disabled for the duration of the game. The Nova Strike is also unavailable. If Zero is chosen instead, the armor will become damaged in the first stage and made unusable for the remainder of the game.

Armor Parts
Helmet Part, in Cyber Peacock's stage: If the third section in the first part of the level is completed fast enough to receive an S rating, the Helmet Capsule will appear in the next area.
 * Increases X's special weapons capacity, allowing him to fire endless uncharged special weapons and use less energy when firing charged weapons. In X5, this is reduced to a 50% energy consumption reduction.

Body Part, in Magma Dragoon's stage: Found in a passage above and to the right of where the Ride Armor is found. It is reached by dash-jumping in the ride armor from the highest point and ejecting from it in mid-air. Enter the passage and break the wall with a charged Twin Slasher to find the Body Capsule.
 * Allows X to use a Giga Attack, the Nova Strike. It is a rushing, invincible, damage-inducing attack, with limited energy that is restored over time. The amount of damage X's receives is also cut in half. In X5 the Nova Strike is removed completely.

Arm Part, in Storm Owl's stage: In the second part of the stage, right before the laser-based miniboss, there is a spike-lined vertical passage. To reach the top, fire a Lightning Web right in front of one of the spiky walls and use it to ascend the passage. At the top, the are two capsules that the player can choose:
 * Capsule 1: Allows X to charge up four charged shots at once. Four icons of plasma will appear next to X's life gauge that are used to keep track of the number of X's shots. Whenever X fires while an icon is visible, he will fire a charged shot.
 * Capsule 2: Upgrades X's charged shots to the Plasma Shot. This shot is much larger and more powerful than the standard blast, and will leave up to 3 damaging orbs in its wake whenever it comes into contact with an enemy. In X5 This is the Arm Part X keeps, but it is weakened to leaving only 1 ball of plasma behind per shot.

Leg Part, in Web Spider's stage: Keep to the right throughout the beginning of the stage. There will be a break in the wall, and the Leg Capsule will be within it.
 * X can air-dash and hover by double-jumping. He can move while hovering, but the amount of time he'll stay airborne is reduced.

Trivia

 * The armor is actually unnamed in Mega Man X4, as armor naming didn't begin until X5. As such, the X4 armor has no name, just like its predecessors, simply being referred to as the "X4 Armor".


 * The armor is often called the "Force Armor" by fans and in some sources. This is a misunderstanding however, as the Japanese word "fōsu (フォース)" can be easily misinterpreted to mean "force" when viewed out of context.


 * In Mega Man X4, the colors of the Arm Parts for the armor are different when equipped with either the Stock Shot or the Plasma Shot in order to distinguish the two. For the Stock Shot, the forearms are white and the hands are blue. For the Plasma Shot, however, the forearms are black and the hands are red.
 * In Mega Man X5, however, the completed Fourth Armor's Arm Parts are white-and-blue and the type of shot that is built-in is the Plasma Shot.


 * Since the Ultimate Armor is the most recurring armor in the series (and the fact that it is essentially an upgrade to the Fourth Armor), most of the Fourth Armor's abilities (Plasma Shot, Nova Strike and Hover) are also the most recurring abilities in the series.