Gate Glitch
The Gate Glitch, sometimes referred to as "Blue Gate Glitch" if the gate in question involves a blue switch, or "Green Gate Glitch" ("GGG" for short) if the gate in question involves a green switch, is a technique to open gates from the opposite side the switch is on (and without using Wave Beam for blue gates).
This glitch is mandatory for categories such as Any% GT Code and GT Classic for accessing the Golden Torizo code. It is also essential in Reverse Boss Order for accessing Screw Attack, the recharge station nearby, and the Ripper 2s that act as a Super Missile refill.
Blue gates can be opened by both Missiles and Super Missiles from the opposite side, while green gates can only be opened with Super Missiles.
Contents
Classic Gate Glitch
This method only works on gates where the switch is on the left side.
To perform the gate glitch, Samus must first stand a couple of pixels to the right of the gate while facing left, and have Missiles or Super Missiles selected (whichever is applicable). Jump while holding angle up, then move left and press shot right before her head hits the ceiling (while still holding jump and angle up).
There are a number of different ways you can execute the gate glitch. Find the one that you are the most consistent in executing. Here are a few you can try: Example I (Rising) Example II (Spin Jump) Example III (Falling)
It may take a couple of tries before one actually hits the button since the timing is rather precise, so make sure you have enough ammo before attempting the glitch.
Other Gate Glitches
With the right positioning and if there is enough space, a super can be fired and obtain enough speed to pass through the gate and activate the switch. The only use for this in the vanilla game is to open the gate in Pink Brinstar Hopper Room using a setup that fires a Super Missile diagonally while lined up against the wall, however the gate can also be opened with a horizontal super. None of the other right facing gates in the game have enough space to the left of the gate for the Super Missile to gain enough speed. See here for more information.
Using a frozen enemy, the gate exiting Maridia in East Tunnel can be opened from the left, requiring precise positioning and 3 frame perfect inputs, or only one using a pause.
Grappling Beam and Speed Booster can be used to open the gate in Green Hill Zone.
G-Mode
In direct G-Mode, once PLMs are overloaded, beam shots will pass through gates. As G-Mode is still active, shooting the gate switch will do nothing. However with good timing, you can fire a shot through the gate, then activate X-Ray once the beam passes fully through the gate to deactivate G-Mode, so the beam then hits the gate switch and activate the gate.
In indirect G-Mode, gates don't appear, and you can just walk right through. The above direct G-Mode trick can also be used, but without having to overload PLMs as the gate isn't even there. This is almost never useful, since you can just walk through the gate, but it is used as a "loophole" to the rules for All Gate Glitches RTA, which state that "A gate glitch is defined as opening a gate from the unintended side."
PAL Only Gate Glitches
The following methods are only possible on PAL.
Using the Zeros and Ice Beam, the gate in Caterpillar Room can be opened.
By freezing an enemy and running into the gate, Samus prioritizes collision with the enemy and is able to clip far enough into the gate for it to open on its own. This can be done on NTSC as well but requires Speed Booster, as shown below.
Non-vanilla Gate Glitches
The following gate glitches are possible with no modification to Samus' physics or gate mechanics, however none of the gates in the vanilla game meet the criteria for these. These tend to find use in sequence breaking romhacks.
