Door

A door (or hatch) is a pathway which leads Samus into new rooms. They have appeared in every Metroid game to date except Metroid Prime Pinball. Doors almost always feature low-level energy shields that can be disrupted by weapon fire. The most common type of door being a blue door, which can be opened with any type of weapon. Almost as commonplace is the red door. In the original Metroid, and Super Metroid they had to be opened with 5 missiles.

In Metroid Fusion, the hatches weren't opened with weapons. They were opened by unlocking their color security level. Afterward they could be opened with any weapon.

There are various types of doors that Samus will encounter in her travel across the planets.

Blue Doors
Encountered in every game, these basic doors can be opened with any weapon.

Purple Doors
Violet doors that are opened with the Wave Beam. Found in Metroid Prime.

White Doors
White-fringed doors that are opened with the Ice Beam. Found in Metroid Prime.

Red and Orange Doors
These red or orange doors are opened with the Plasma Beam. Found in Metroid Prime and Metroid Prime 3: Corruption.

White Door (Metroid Prime 2: Echoes)
White colored doors that are opened with the Light Beam. Found in Metroid Prime 2: Echoes.

Black Doors
Black colored doors that are opened with the Dark Beam. Found in Metroid Prime 2: Echoes.

Gray Doors
Black-and-white colored doors that are opened with the Annihilator Beam. Found in Metroid Prime 2: Echoes.

Green Doors
Green colored doors that are opened with the Nova Beam. Found in Metroid Prime 3: Corruption.

Red Blast Shield
These red colored doors are found in Metroid, Metroid II: Return of Samus, Super Metroid, Metroid: Zero Mission, and Metroid Prime 2: Echoes. These doors are opened with 5 normal Missiles (1 in Zero Mission and Echoes) or 1 Super Missile.

Green Blast Shield
Green doors from Super Metroid, Metroid: Zero Mission, and Metroid Prime 2: Echoes, these require a Super Missile to open.

Multi-Lock Blast Shields
Blast shields that can only be destroyed by hitting the locks simultaneously with Seeker Missiles. Found in Metroid Prime 2: Echoes and Metroid Prime 3: Corruption.

Yellow Blast Shield
These doors can be found in Super Metroid, Metroid: Zero Mission and Metroid Prime 2: Echoes. They can be opened with a Power Bomb.

White Blast Shield
These doors are found in Metroid Prime 3: Corruption. They are vulnerable to the Ice Missile and, possibly, other cold-based weaponry, although this has yet to be proven.

Mounted Blast Shields
Blast shields that are destroyed by using the Grapple Lasso to generate enough stress to pull them from their mounts. Found in Metroid Prime 3: Corruption.

Trivia

 * In the 3D Metroid games, the doors acted as hidden loading screens, which is why some took so long to open.


 * The doors of Elysia in Metroid Prime 3: Corruption strongly resemble the doors of Metroid Prime, hence the fact that both planets were also old Chozo colonies.
 * The doors of Pirate Homeworld in Metroid Prime 3: Corruption also have some resemblance to those of Metroid Prime 2: Echoes, the designs of which the Pirates most likely stole.
 * In Metroid Prime 2: Echoes if a Metroid touches a door, it will be instantly killed, this can be performed best in the Space Pirate base in Agon Wastes.