Out of Bounds
By using Secret Worlds, you can leave the intended boundaries of the game. This allows for various skips and routing options that would not normally be possible. Going out of bounds is a necessity in the fastest speedrun routes, with notable examples being the Frigate Wallcrawl in Metroid Prime, Item Loss Skip in Metroid Prime 2: Echoes and the Novacrawl in Metroid Prime 3: Corruption. Traveling out of bounds is often known as wallcrawling, and is often more difficult than standard in-bounds movement due to various factors. This page will explain all of the necessary concepts regarding out of bounds movement in the Prime games.
Every room is contained inside of an invisible box. Inside this box, Samus will have normal physics. Outside of this box, however, is what is called the Aether. The physics of Aether is completely different to normal. Notably, there are three distinct properties of the Aether:
- Samus will not be able to jump (her jumpstate is set to 0)
- While unmorphed, Samus will slowly float upwards
- While morphed or performing a Screw Attack, you will fall until you are unmorphed
When wallcrawling, it is extremely important to know where the boundaries of the Aether box are at all times. Generally, the boundaries of the Aether box will align with the doors of each individual room, as they will align with the edge of the room's collision. This isn't always the case however, so it is important to understand each room's box on a case by case basis. If multiple rooms are loaded at once, the boxes will intersect each other, which is important to know while wallcrawling. If you aren't sure what the dimensions of a particular room's box is, it is recommended to use Prime World Editor to learn them.
It is also important to note that, while floating in the Aether, you stop floating for a single frame when pressing B. This is most relevant during portions of wallcrawls that involve jumping from the bottom of the room's box, as this means that pressing B will lose a frame for each time it is pressed before Samus reaches the box.
There is a 3 frame window to perform an Aether Jump. While in the Aether, Samus has Jumpstate 0 and is grounded. Upon leaving the Aether Samus will enter Jumpstate 3 before falling known commonly as the Coyote window which gives Samus a few frames to jump when walking off of a ledge. To perform an Aether jump you must either jump during Jumpstate 0 and completely leave the Aether the next frame, or jump during the Coyote window. This leaves a 3 frame total window for Aether Jumping. This can be used to climb the Aether Box of a room by jumping every time you leave the Aether.
In Prime 1, missing the 3-frame window will put you in Jumpstate 2 or "freefall" where in the Prime 1 engine Samus loses directional control and cannot stop herself from falling all the way to the bottom of a room. Because of this, it's often preferred to use the corner of the room's box to Aether Jump in a diagonal direction so that if you miss an Aether Jump, you only fall a short distance before entering back into the Aether.
Echoes and Corruption
In Echoes and Corruption, Jumpstate 2 does not restrict your control over Samus while falling. This means you can go back into the Aether without the need for a corner to catch yourself if you miss the window to Aether Jump. Due to this difference, Aether Jumping in these games is usually done without a corner and can be easier to learn with.
TODO: videos demonstrating aether jumping in all 3 games
Falling in the Aether
Despite that Samus floats while in the Aether, if she falls too far down the Aether (approximately 20 seconds of falling) the game will softlock. This is because the distance you are able to float is vastly smaller than the distance that the game allows you to fall. When Samus passes this threshold, she will no longer be able to go upwards, only downwards.
Additionally, Samus' point of view starts getting glitchy after falling for several minutes. If Samus falls down long enough, the animations will appear to be glitched as a result of being so far out of bounds.
Every bit of collision in each room is made up of triangles, with each triangle having an inside and outside. While the inside of each collision triangle behaves just as expected, the outside of each triangle is "sticky" meaning that she will have a very limited capacity to move and the game will often constantly attempt to reposition Samus away. Since you can't move on these sticky surfaces, it is preferred to move on standable spots, which are surfaces that behave just like in-bounds collision. These can be found on extended flat surfaces, edges between 2 sticky collisions, or the top of the seam of a piece of collision such as a vertical wall. Some standable spots can even be a point where different collision triangles intersect with eachother. Each individual room has its own set of standable spots, and knowing where these are is essential for fast movement while wallcrawling. Sometimes you may be able to intuit where these spots are as a general rule, but other rooms require memorization of where these spots are as they may not be obvious. If all else fails, you can use the Morph Ball Bombs to quickly break away from sticky collision if necessary, but beware that Morphing while out of bounds carries the risk of softlocking if in the wrong place.
When wallcrawling, it is necessary to be able to load the room that you wish to go next.
Physically touching a loading trigger will cause the game to have the room load like normal. Depending on the room, individual strats may need to be performed in order to touch these triggers. For example, during the Ice Beam Before Flaahgra wallcrawl in the room Furnace, the loading trigger has to be touched in order to load East Furnace Access. All rooms in Prime 1 are based on loading triggers, but only some rooms in Echoes and Corruption use these, instead using proximity loads.
Proximity Loads (Echoes and Corruption)
Many rooms in Echoes and Corruption (but not all) will be based on proximity loads, which are not tied to physically placed triggers within the room itself. In this case, simply travel to the room of your choice and it will automatically load for you. If you want to know whether a room is based on proximity loads or not, go into Prime World Editor and look for load triggers as you would in Prime 1. If none exist, then the room is based on proximity loads.
Force Loading Rooms
To force load a room, shoot at the door and get close to it, then wait for the room to load. This entails being near the side of the door, as the sides of the door will be enveloped by a trigger that causes the door to open. Once you hit this trigger, quickly stand on top of the door, or stand on the other side of the door if you want to go in-bounds.
Force loading rooms is prone to crash depending on the circumstances. This is because there has to be enough free memory available to quickly load the room and unload any extra rooms that may be loaded. If a room is too large or has too many objects, this can cause the game to crash. Therefore, this method of loading rooms is only recommended in specific circumstances where the game will not crash.
Once a room is done loading, it will stay invisible until it is transitioned to. Depending on the game, it can still be tracked in different ways:
- In Prime, shooting against collision where the next room would be, and the shots make contact
- In Echoes and Corruption, shooting behind the door and the shots unload immediately, then the room has loaded
The game always keeps track of which room that it thinks you are in. This can be seen on the map on the top right. The game will only load rooms which are directly connected with the room the game thinks you are in on the map. Therefore, when wallcrawling through rooms, you have to do what is known as a transition between rooms. Usually this is done by jumping on the respective side of the door, but sometimes there are different setups have to be used especially on vertical doors.
It is important to know that rooms behave differently when not transitioned into. Most notably, the game will not reposition you when you morph next to a wall, which can be abused to obtain Infinite Speed in certain areas.
Getting Back In-Bounds
Depending on the circumstances of the wallcrawl, you may wish to get back in-bounds sooner or later. There are many methods of doing this.
Falling Back In-Bounds
The simplest way to get back in-bounds is by falling back into any room that doesn't have a physical ceiling. This is most often done by getting on top of the box and then proceeding to morph.
Another way is by letting the room load around you, occupying the space where the room would be before it is even loaded. This is usually done by force loading a room and proceeding to wait. Once the room loads, touch the door to the active room so the game transitions you to the loaded room. A good example of this is at the end of the Frigate Wallcrawl, where you get back in-bounds by getting in front of the door leading to Exterior Docking Hangar.
If the room is already loaded, but not transitioned into, it is possible to do what's called a Ceiling Warp. To perform a Ceiling Warp into a room, first be sure you are not already transitioned into the room you are trying to warp into. This is important, as when a room is not transitioned into, its collision is weaker. Then, morph into an appropriate piece of collision, preferably sloped collision, with some momentum. In some cases, boosting or using the Morph Balll Bombs can help to successfully ceiling warp into the room if it doesn't work the first time. A good example of this is during the Wave/Sun wallcrawl, where in Chozo Ice Temple a ceiling warp is done to open the gate and prepare for the Infinite Speed glitch just after.
Some cutscenes will automatically place you in-bounds once triggered. An example of this is during the Dark Beam wallcrawl, when the trigger to activate the Dark Samus 1 boss fight has been activated. Once the cutscene is done, it will automatically place Samus where the fight takes place, even if the room hasn't been transitioned to. In addition, this trigger also automatically transitions to Main Reactor if it isn't already transitioned to.
- See Also: Boost Ball#Infinite Boosting
In Prime 1, the Boost Ball has an extremely short cooldown, allowing for what is known as Infinite Boosting. This can be used in some cases to bypass collision and go through walls. To Infinite Boost into a room, land on a standable spot directly next to a wall and morph against it. Then, keep boosting and eventually unmorph to clip through. This might not work every time, and the number of boosts required to clip through may change depending on angle and position, as well as the circumstances of the room and/or collision. In some cases, unmorphing is not required. This is mainly done with a room you are not currently transitioned into, as this means the collision of the room is weaker. One example of this is in the room Elite Research, in which this is used to get past the wall that is blocking Samus.
There is a special case where one can Infinite Boost to get back inbounds in Echoes, even with the map on the correct room.
This is a Boost clip, due to the fact that the Prime games don't have a sideways speed cap (on very specific conditions/circumstances) you can use this to your advantage to clip into a room with high speeds Boosting Sideways into the desired collision, it only works when the Morph Ball is on ground and when boosting into a flat wall.
Terminal Fall Abuse
- See Also: Terminal Fall
This method is only applicable in Echoes and Corruption, as Prime does not have any Terminal Fall triggers in any room. Triggering Terminal Fall respawns Samus at the default respawn point of the room. Both games behave differently when it comes to respawning.
Every room with Terminal Fall has a default respawn point, so as long as one touches the Terminal Fall trigger, Samus will be placed back inbounds at that point.
Unlike Echoes, rooms with Terminal Fall do not have a default respawn point. Instead, hitting Terminal Fall without touching a respawn trigger causes Samus to take damage from the Terminal Fall and keep falling to the bottom of the Aether box. The only way to respawn back inbounds is to touch a respawn trigger BEFORE triggering Terminal Fall. In some cases, the respawn triggers can be skipped, even while inbounds. This is known as Fall Respawn Skip.