X-Ray Climb
X-Ray Climbing is a technique that allows Samus to go Out of Bounds. It is mainly used while getting stuck inside of a door. Most categories that go Out of Bounds do so by means of X-Ray Climbing, such as Any% Glitched and RBMBO.
To perform X-Ray Climbing, make sure to pick-up the X-Ray Scope. Get stuck in a door, and crouch. Use the X-Ray Scope, face the other direction and immediately stop scoping. If done right, Samus should now be forced into a standing position which moves her up by 5 pixels.
Runners will need to be careful not to morph part way through the X-Ray Climb, which would result in a softlock. To avoid this, many runners will pause and turn off Morphing Ball to avoid this.
Item Randomizer, certain Low% categories, as well as some RBO routes sometimes make use of inbounds X-Ray Climbing to get through The Precious Room after defeating Draygon due to the lack of Gravity Suit.
If you're trying to see if you're high enough to jump out of the wall, do it from a crouch. If you're still fully embedded in the wall and you jump while standing, it will put you in a crouched pose that won't allow further X-Ray use.
Because of the properties of X-Ray Scope to change Out of Bounds blocks, non-optimal X-Ray Climbing that leaves X-Ray activated for seconds at a time can alter the layout of the Out of Bounds, causing standard routes or setups to have new blocks in their path.
Door Stuck
There are 2 levels of being stuck in a door: Stuck and Deep Stuck.
A stationary spinjump and walljump check inside the door shell of a rightwards transition is enough to get Stuck inside of a door for X-Ray climbing most rooms. You'll need to do the walljump check low enough to avoid having the top of the doorframe put you in a forced-crouch pose, which would prevent the use of X-Ray.
However for leftward door transitions, or if the room geometry requires it (see the any% glitched X-Ray climb,) you need more backwards momentum during the transition. Taking enemy damage or performing a precise shinespark as the transition begins both are ways to get Deep Stuck in doors.
