A **Cappy return cancel** (often abbreviated as **CRC**) is a technique that can be exploited to allow Cappy to gain an extremely large amount of distance away from Mario in two-player mode. This distance 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.

## Explanation Edit

In two-player mode, Cappy cannot normally exceed a certain distance away from Mario. However, if Cappy becomes stuck behind something, his path back to Mario will be blocked and he will be able to exceed the normal distance range. In this case, Cappy is in his *extended state*, meaning that while he will attempt to return to his normal range if there is a clear line of sight, he will simply stay put if there is not.

If the X or Y button is pressed while Cappy is in his extended state, Cappy will enter his *returning state* and attempt to return to Mario's head. Normally, when Cappy enters his returning state, he will simply fly back to Mario's head. If this is done while Cappy is either stuck behind something or extremely far away, Cappy will not be able to fly back to Mario's head in time and will simply teleport back to Mario after a few seconds.

It is possible to cancel this teleportation in order to revert Cappy back to his extended state. This is what is known as a Cappy return cancel. In order to perform one, the X or Y button must be pressed on Cappy's controller at the exact moment that Cappy attempts to teleport back to Mario (the window is estimated to be two frames). Additionally, Mario must be in certain animations at the moment of the return cancel (crouching, rolling, backflips, sideflips, spin jumps, diving, bonking, and holding objects all work for this purpose); these animations prevent Mario from using his arm to place Cappy back onto his head after Cappy returns. Once the return cancel is performed, Cappy will not land on Mario’s head, but will instead teleport to another position away from Mario.

## Exploitation Edit

While the location Cappy teleports to may seem random at first, it actually follows a consistent geometric rule. Once this rule is learned, it can be exploited to teleport Cappy to arbitrary locations. There are two geometric interpretations of this rule:

- Draw a "line of sight" that goes through Mario in the direction that he is looking and travels infinitely both in front of and behind him. After the return cancel, Cappy will teleport to the location on this line of sight that he is the closest to.
- Draw a sphere such that Mario and Cappy are at exact opposite points along its surface. After the return cancel, Cappy will teleport to the far point on the surface of the sphere that is intersected by Mario's line of sight.

Both of these are different geometric interpretations of the same rule. The diagrams to the right provide visual explanations of the two rules, and it is evident from the diagrams that both rules describe the same phenomenon.

Mathematically, the rule is described by the following vector formula, where $ {M} $ is Mario's position, $ {C} $ is Cappy's original position before the return cancel, $ {C'} $ is Cappy's new position after the return cancel, and $ {F} $ is a unit vector representing the direction Mario is facing:

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

If the point that Cappy attempts to teleport to does not have a clear line of sight back to Mario (i.e. there will be an obstruction when Cappy attempts to return to Mario), Cappy will stay in his original location instead of teleporting. This can be used to reset Cappy from the returning state to the controllable state without changing Cappy's position.

Cappy return cancels can be abused to send Cappy to distant locations along the sphere's surface. However, since the size of the sphere depends on the distance between Mario and Cappy, the uses of the trick are limited unless it is possible to get Cappy very far away from Mario. Usually, getting Cappy far enough from Mario requires getting him stuck behind a wall, which would mean that Mario would have needed to walk near that wall to get Cappy stuck in the first place. This is often impractical; fortunately, there are a few ways to get Cappy far from Mario without Mario needing to travel to that location.

### Odyssey teleportation Edit

If any of the four face buttons are pressed on Cappy's controller the exact frame that Cappy becomes controllable (such as after warping to a checkpoint), Cappy will instantaneously teleport to the Odyssey. When this happens, Cappy will be in his returning state, meaning that a return cancel will need to be performed to prevent Cappy from teleporting back to Mario. This is most useful if Cappy gets stuck behind something on his way back to Mario, but if Mario is sufficiently far away from the Odyssey, Cappy can repeatedly ground pound to retain his distance.

### Sloped Cappy return cancels Edit

Another way to gain distance as Cappy is to repeatedly ground pound into the void many times. Because there is no limit to how many times Cappy can ground pound, Cappy can reach an unlimited vertical distance below Mario.

Normally, the direction that Mario is facing is strictly horizontal. Using the sphere analogy, if Cappy is directly beneath Mario due to repeatedly ground pounding, Mario will be at the very top of the sphere and his line of sight will not intersect any distant point on the sphere. This means that after the return cancel, the location that Cappy teleports to will simply be right next to Mario.

However, if Mario is standing on a slope, this direction will point at a diagonal angle, and can intersect a different part of the surface of the sphere. Combined with repeated Cappy ground pounds, slopes allow one to send Cappy an extremely long distance away from Mario. As seen in the diagram to the right, 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.

## Uses Edit

### Minimum Captures Edit

Cappy return cancelling is used in various Minimum Captures runs to access Morning Metro to skip the Sherm capture, as well as skip five spark pylons in Bowser's Kingdom. It is also used to make Madame Broode Skip much easier.