Cappy return cancel

A Cappy return cancel, often abbreviated as CRC, is a glitch that can be exploited to allow Cappy to teleport to locations very far away from Mario in two-player mode. This can be used to activate Checkpoint Flags, trigger captures, and perform other actions at a great distance. Cappy return cancels were discovered by glitch hunter Syrkl.

The glitch involves canceling the action of Cappy teleporting to Mario's head, which most often occurs when Cappy is called to return to Mario but is unable to due to an obstruction or from being too far away. By doing this, instead of teleporting to Mario's head, Cappy can teleport to other arbitrary locations.

Causes for Cappy's return

There are two primary reasons Cappy can return to Mario, both allowing a CRC to be performed if the return is successfully canceled.

Manual return

When Cappy is first separated from Mario, he is put into flight mode. In this mode, Cappy can freely maneuver as long as he stays within a certain horizontal range of Mario. He will stay in this mode indefinitely unless he hits an object that triggers a specific action, or until he is prompted to return to Mario by pressing X or Y or shaking the controller. If he is prompted to return to Mario, he will enter return mode and attempt to fly directly back toward Mario.

In most cases, Cappy will successfully fly back to Mario, but him returning this way is undesirable for CRCs, since they rely on Cappy attempting to teleport to Mario from afar. While in return mode, Cappy will teleport back onto Mario's head if he is stuck somewhere for around three fourths of a second, or if he does not return to Mario at all after around three seconds (such as by being very far away). The majority of CRCs involve Cappy returning to Mario in this manner, and players often use a metronome to time the interval between when Cappy is put into return mode and when the return needs to be canceled.

Automatic return

Certain transitions, such as initiating a boss fight or entering a loading zone to another area in the same stage, will cause Cappy to be placed back onto Mario's head automatically, thus teleporting from the location he was previously at. This can be canceled as well, in what is known as an instant CRC, or ICRC.

A special case of the instant CRC technique known as an Odyssey CRC, or OCRC, can be performed just after warping to a Checkpoint Flag. When the area is loaded in while warping to a Checkpoint Flag, Cappy is briefly initialized near the position of the Odyssey. Immediately after control of Mario is gained, Cappy is teleported onto Mario's head, which can be canceled.

Mario actions

In order for a CRC to be successful, at the moment Cappy's return is canceled, Mario must be performing an action that will prevent the animation of him placing Cappy back onto his head. Mario also must not be in a capture, as captures have their own animation for placing Cappy back onto their head. Although crouching is most commonly used for this purpose, any of the following actions will work:

• Crouching
• Rolling
• Diving (excluding automatic dives into water)
• Performing a backflip
• Performing a sideflip
• Performing a spin jump
• Jumping on a Bounce Flower
• Bonking (including underwater)
• Wall sliding
• Sliding down a slope
• Ledge grabbing
• Climbing up from a ledge grab
• Jumping up from a ledge grab
• Climbing a pole or tree
• Swinging from a pole
• Holding an item
• Taking damage (including underwater)
• Damage from lava
• Death
• Sitting on a bench
• Riding a scooter
• Riding Jaxi
• Riding a Seaside Kingdom fountain

Canceling Cappy's return

There are two primary ways to cancel Cappy's return, each with different behavior. Both of these require executing an input within a five-frame window at the moment Cappy attempts to teleport back to Mario.

Using a jump input

The simplest way to cancel Cappy's return is to press one of the jump buttons (A or B) on the controller that corresponds to Cappy. This will cause Cappy to teleport to the location he is already at; in other words, he will stay in place, but will seem to disappear for a brief moment.

Using a flight input

The more useful method of canceling Cappy's return is using a flight input (X or Y, or a motion shake input). Rather than simply keeping Cappy in place, this will cause him to teleport to a new location that follows a specific geometric rule, which can be exploited to teleport Cappy to arbitrary locations.

Geometric rule

The line analogy

The sphere analogy

The rule depends on the direction Mario is facing, referred to as the line of sight. This is imagined to be a line that goes through Mario and extends infinitely both in front of and behind him. This line is normally horizontal but can extend diagonally if Mario is standing on a slope.

There are two equivalent geometric interpretations of the rule:

1. Line analogy: After the CRC, Cappy will teleport to the point on the line of sight that he is closest to.
2. Sphere analogy: Imagine a sphere such that Mario and Cappy are at exact opposite points of its surface. After the CRC, Cappy will teleport to the far point on the surface of the sphere that is intersected by the line of sight.

The diagrams provide visual explanations of the two rules, and it is evident from the diagrams that both rules describe the same phenomenon.

Although not necessary to gain an intuition for the mechanism, the geometric rule can be described mathematically. The location Cappy will teleport to is determined by the following vector formula:

$C=M+((C_{0}-M)~\cdot ~F)F$

where $M$ is Mario's position, $C_{0}$ is Cappy's original position before the CRC, $C$ is Cappy's new position after the CRC, and $F$ is a unit vector representing the direction Mario is facing. The symbol · represents the vector dot product.

If a direction is being held on the left joystick on Cappy's controller at the moment of the CRC, the vector $F$ will instead be equal to that direction rotated onto the plane Mario is standing on. This is also a unit vector and is necessarily parallel to the surface Mario is on, meaning that this technique cannot be used to send Cappy to a location that would not be possible from simply angling Mario in the desired direction.

Blocked CRCs

Sometimes, when performing CRCs with a flight input, Cappy will stay in his current location instead of following the geometric rule, as if the CRC was performed with a jump input instead. The exact cause of this is not known, but it seems to only occur in instances where there is collision between Mario and the targeted position of Cappy.

It was previously believed that this occurred any time there was collision between Mario and the targeted position with a surface normal facing away from Mario, meaning that Cappy would not have a clear flight path back to Mario after the CRC. This became known as the reverse collision theory. However, despite this theory sometimes being able to predict whether a CRC will be blocked, it has been noted that it is not completely correct, since in some cases a CRC will be successful despite the presence of so-called reverse collision.

Gaining distance

The geometric rule dictates that Cappy's new position can be no farther from Mario than his original position. Because of this, in order for Cappy return cancels to be used in any meaningful way, it is necessary for Cappy to already be far away from Mario, although not necessarily in the desired direction. Since there is a limited horizontal range for moving Cappy normally, one of a few specific techniques must be used to get Cappy far away from Mario in preparation for a CRC.

Getting Cappy stuck

The simplest way to get Cappy far from Mario is to place him in a location where he will not have a clear return path to Mario, such as in a corner or behind a wall, and then walking away from him. This will cause Cappy to get stuck indefinitely, as long as Cappy remains in flight mode and Mario does not move to a location where Cappy is out of range but has a clear return path.

However, this method has the limitation that Mario must be able to reach a viable place to leave Cappy, which must be in the same general direction as the target location from where the CRC will be performed. It should also be noted that Cappy will be unable to move while stuck.

Ground pounding

A diagram showing the distance yielded by a sloped CRC using different slopes

A powerful way to gain distance as Cappy is to repeatedly ground pound. Unlike with horizontal distance, there is no limited range for how far Cappy can be below Mario before attempting to rise back up (although he will if Mario jumps). This means that ground pounding Cappy into the void can be used to send Cappy arbitrarily far during a CRC.

Due to the geometric rule, Mario needs to be standing on a slope at the time of the CRC for this technique to work, as a horizontal line of sight will result in the target position coinciding with Mario's position rather than being at a remote point.

As seen in the diagram (which depicts the sphere analogy), the optimal horizontal distance is achieved when Mario is sloped at a 45-degree angle, and the horizontal distance diminishes the flatter or steeper the angle becomes.

Instant CRCs

Instant CRCs are a subset of CRCs that do not require Cappy to gain distance from Mario in the conventional ways. Known instances where you can trigger an ICRC include: Warping, (some) Triggered Cutscenes, and Story Moons. Unlike other CRCs, these are frame perfect. There are three types of Instant CRCs, typically referred to as: A/B ICRCs, X/Y ICRCs, and Shake ICRCs. A/B ICRCs will teleport Cappy back to his stored X/Z position and Cappy will automatically enter return mode. X/Y ICRCs will perform a CRC in front of Mario and cause Cappy to automatically enter return mode. Shake ICRCs teleport Cappy back to his X/Y/Z position but does not automatically enter return mode. It is unknown why return mode is triggered with button inputs and not shakes, when for other CRCs it is the opposite.

ICRCs are mostly used to either keep Cappy in a position when Cappy would typically teleport back to Mario, or to teleport Cappy to the Odyssey, since that is Cappy's saved position during warps.

Timing approaches

There are two distinct approaches that can be used when canceling Cappy's return. The timed approach has the most flexibility, but the shake-to-win approach is easier for specific CRCs.

Timed

The most fundamental approach to performing a CRC is to press X or Y once at the moment Cappy attempts to teleport back to Mario. Using this method, known as a timed CRC, will leave Cappy in flight mode after the CRC; this is necessary to perform certain actions as Cappy such as ground pounding, or if the player needs time to prepare a subsequent CRC.

This is the approach for which players most often use a metronome to assist with timing, due to the window for the final button press being only five frames. Some players have created metronome audio files specifically for the three-second interval used in the majority of CRCs.

Shake-to-win

There is a second approach that eliminates the need to perfectly time the final button press. This method is known as the "shake-to-win" or S2W method, and involves repeatedly shaking the controller or mashing the X/Y buttons to cancel Cappy's return.

Shake-to-win CRCs also have the additional advantage of causing Cappy to immediately home in after teleporting, which is very useful when targeting captures, Checkpoint Flags, or other similar objects.

However, there is a drawback to this approach which makes it nonviable for certain setups. When performing a timed CRC, the X or Y button is pressed exactly once to cancel Cappy's return, which causes Cappy to transition from return mode back to flight mode. However, during a shake-to-win CRC, the repeated inputs will cause Cappy to immediately revert to return mode again. In addition to making it impossible to ground pound as Cappy after the CRC, this is equivalent to initiating a second CRC, meaning that Cappy will return to Mario's head unless his return is canceled again. For setups that utilize multiple CRCs, this means the player only has a short window to properly adjust Mario's position between CRCs.

Uses

Cappy return cancels are used in various Minimum Captures runs (most notably Minimum Captures Any%) to access Morning Metro to skip the Sherm capture, as well as skip five spark pylons in Bowser's Kingdom. One can also be used to make Broode Skip much easier.

However, the usage of Cappy return cancels is not limited to Minimum Captures. Cappy return cancels can also be used for other Low% categories, including Minimum Jumps and Minimum Left Stick, or to reach Warp Painting islands early, among other uses.

The following is a list of instances where Cappy return cancels are useful:

Kingdom	Application	Explanation	Video
Cap Kingdom	Minimum Left Stick, Minimum Music, loading zone bypass	Activates the Checkpoint Flag at the top of Top-Hat Tower to skip the interior section as well as the bridge.	Link
Cap Kingdom	Minimum Captures All Moons	Captures a distant spark pylon in Push-Block Peril in order to skip the first wire.	Link
Cascade Kingdom	Minimum Captures, Warp Painting bypass	Activates the Checkpoint Flag on the Warp Painting island for an extra moon. Known as Broode Skip.
Cascade Kingdom	Boss arena escape	Activates the globe on the Odyssey during the Madame Broode fight, in order to escape the arena.	Link
Sand Kingdom	Warp Painting bypass	Activates the Checkpoint Flag on the Warp Painting island from the ground.	Link
Lake Kingdom	Minimum Music	Activates the Water Plaza Terrace Checkpoint Flag from the Courtyard.	Link
Wooded Kingdom	Minimum Captures	Activates the Checkpoint Flag on the Observation Deck in order to reach it early.	Link
Metro Kingdom	Minimum Captures, Star%	Activates a Checkpoint Flag on the mainland from the Warp Painting island to access the kingdom early. Known as Morning Metro.
Metro Kingdom	Star%	Captures a pole on the mainland from the Warp Painting island. Faster variant of Morning Metro known as Pole Snipe.
Metro Kingdom	Star%	Captures a spark pylon on the mainland from the Warp Painting island. Fastest variant of Morning Metro known as Pylon Snipe.
Metro Kingdom	Loading zone bypass	Captures a spark pylon at the top of New Donk City Hall to skip the interior section.	Link
Metro Kingdom	Loading zone bypass	Activates the Checkpoint Flag at the top of New Donk City Hall to skip the interior section.	Link
Metro Kingdom	Minimum Captures All Moons	Captures a distant spark pylon in the outfit room in order to skip the first wire.	Link
Seaside Kingdom	Minimum Captures shortcut	Activates the Checkpoint Flag on the Warp Painting island, allowing early access to it without the use of a Gushen.
Seaside Kingdom	Minimum Captures shortcut	Activates the Checkpoint Flag on top of the lighthouse in order to skip the underwater tunnel without the use of a Gushen.
Luncheon Kingdom	Warp Painting bypass	Activates the Checkpoint Flag on the Warp Painting island from the mainland.	Link
Ruined Kingdom	Minimum Jumps	Captures the Mini Rocket at the top of the Roulette Tower room in order to skip the 2D section.	Link
Bowser's Kingdom	Minimum Captures	Activates the Third Courtyard (Front) Checkpoint Flag from the start.	Link
Bowser's Kingdom	Minimum Captures	Activates the Third Courtyard (Rear) Checkpoint Flag from the start. Known as 1 to 3.	Link
Bowser's Kingdom	Minimum Captures	Activates the Third Courtyard (Rear) Checkpoint Flag from the Third Courtyard front.	Link
Bowser's Kingdom	Minimum Captures	Activates the Second Courtyard Checkpoint Flag from the Third Courtyard front.	Link
Bowser's Kingdom	Minimum Captures	Activates the Second Courtyard Checkpoint Flag from the Third Courtyard rear. Known as 3 to 4.	Link
Bowser's Kingdom	Minimum Captures	Activates the Souvenir Shop Checkpoint Flag from the Second Courtyard.	Link
Bowser's Kingdom	Minimum Captures	Activates the Main Courtyard Entrance Checkpoint Flag from the shop island.	Link
Bowser's Kingdom	Minimum Captures	Activates the Main Courtyard Checkpoint Flag from the Second Courtyard.	Link
Bowser's Kingdom	Minimum Captures	Activates the Inner Wall Checkpoint Flag from the Second Courtyard. Known as 4 to Inner Wall.
Bowser's Kingdom	Minimum Captures	Activates the Checkpoint Flag that appears in the arena after completing the kingdom from the Main Courtyard.	Link
Bowser's Kingdom	Warp Painting bypass	Activates the Checkpoint Flag on the Warp Painting island from the mainland.	Link
Moon Kingdom	Minimum Capture Types	Captures the spark pylon near the treasure chest in the Underground Moon Caverns to collect the moon in it without a Banzai Bill capture.	Link
Moon Kingdom	Minimum Captures	Collects a cluster of three regional coins near the Moe-Eye in the Underground Moon Caverns from one of the other islands.	Link
Moon Kingdom	Minimum Captures	Collects a cluster of three regional coins in the Banzai Bill section in the Underground Moon Caverns from one of the other islands.	Link
Moon Kingdom	Minimum Captures	Collects a cluster of three regional coins near the Tropical Wigglers in the Underground Moon Caverns from one of the other islands.	Link
Mushroom Kingdom	Warp Painting bypass	Activates the Checkpoint Flag on the Warp Painting island from the mainland.	Link
Mushroom Kingdom	Early Mushroom	Captures the near pair of binoculars on the mainland from the Warp Painting island.	Link
Mushroom Kingdom	Early Mushroom	Captures the far pair of binoculars on the mainland from the Warp Painting island.	Link
Darker Side	Minimum Captures Darker Side	Captures a frog at the end in order to skip the entire interior section without using the version-exclusive Frog Airswim.	Link
Darker Side	Minimum Capture Types, Minimum Captures Darker Side	Captures a spark pylon at the end of the interior section from the starting island.	Link

Theorized uses

There are a few unproven Cappy return cancels that would be useful:

Kingdom	Application	Explanation
Ruined Kingdom	Boss arena escape	Activates the globe on the Odyssey during the Ruined Dragon fight, in order to escape the arena.
Bowser's Kingdom	Boss arena escape	Activates the globe on the Odyssey during the RoboBrood fight, in order to escape the arena.