Ultra Shortcut
- Bugs in alphabetic order
- Harry Potter Effect
- Item Position Bug
- KCL Glitches
- Moiré pattern
- Off-Road Glitch
- Position Jump Bug
- Slow Motion Bug
- Start Line Bug
- Ultra Shortcut
- Underground Camera Bug
- Wiggler Glitch
- Z-fighting
- Advanced information
What is an Ultra Shortcut?
This is a term that is often thrown about within the community, but its actual definition is as follows:
- "An ultra shortcut, or "ultra" as it is sometimes known, is an unintended shortcut resulting from a glitch that allows players to skip the first key checkpoint of a track and successfully gain a lap count despite not having gone through all key checkpoints."
Ultra Shortcuts are not to be confused with corner cutter shortcuts (like the Mushroom Gorge gap jump) or off-road Mushroom shortcuts, as it can be assumed that these were intended to save time when the tracks themselves were being made. Smaller shortcuts that make use of glitches but do not skip any key checkpoints (such as the Bowser's Castle shortcut shown here, or the GBA Bowser Castle 3 shortcut shown here) are not Ultra Shortcuts; however, they are often still referred to as glitch shortcuts a lot of the time.
Nintendo Tracks With Ultra Shortcuts
Mario Kart Wii contains the largest number of glitch shortcuts present on any home console Mario Kart game, with the currently broken tracks being:
| Cup | Track | Status |
|---|---|---|
 Mushroom Cup |
Luigi Circuit | TAS only |
| Moo Moo Meadows | TAS only | |
| Mushroom Gorge | Yes | |
| Toad's Factory | No | |
 Flower Cup |
Mario Circuit | Yes |
| Coconut Mall | Yes | |
| DK Summit | Slower, TAS only | |
| Wario's Gold Mine | Yes | |
 Star Cup |
Daisy Circuit | TAS only |
| Koopa Cape | Yes | |
| Maple Treeway | Yes | |
| Grumble Volcano | Yes | |
 Special Cup |
Dry Dry Ruins | TAS only |
| Moonview Highway | TAS only | |
| Bowser's Castle | TAS only | |
| Rainbow Road | Yes | |
 Shell Cup |
GCN Peach Beach | Yes |
| DS Yoshi Falls | TAS only | |
| SNES Ghost Valley 2 | Yes | |
| N64 Mario Raceway | TAS only | |
 Banana Cup |
N64 Sherbet Land | Yes |
| GBA Shy Guy Beach | Yes | |
| DS Delfino Square | No | |
| GCN Waluigi Stadium | Yes | |
 Leaf Cup |
DS Desert Hills | TAS only |
| GBA Bowser Castle 3 | Yes | |
| N64 DK's Jungle Parkway | Yes | |
| GCN Mario Circuit | Slower, TAS only | |
 Lightning Cup |
SNES Mario Circuit 3 | No |
| DS Peach Gardens | TAS only | |
| GCN DK Mountain | Slower, TAS only | |
| N64 Bowser's Castle | Yes |
Causes of Ultra Shortcuts
Ultra Shortcuts are caused by bypassing the first key checkpoint (checkpoint 00). When the game looks at your progress through a lap, it checks which checkpoints you have passed, and in order for a lap to count, you have to hit specific ones as you complete the track. These are called "key checkpoints" and increase according to number (00, 01, 02, 03 etc.). If you pass the first key checkpoint then miss out checkpoint 03 and complete the lap, you will find that the game will not count it; however, if you skip checkpoint 00 but still pass the final one each lap, then the game will instead assume that you have completed the track successfully and will count the lap accordingly. It is important to know this will only work if a player skips, at most, 95% of the track. If a player skips more than that, the game will assume the player drove backwards.
There are a lot of methods by which checkpoint skipping can occur. Referring back to the Nintendo tracks mentioned earlier, tracks such as Mushroom Gorge, Mario Circuit, Coconut Mall, Wario's Gold Mine, and GCN Peach Beach are all caused by glitches in the game's physics engine, whereas Maple Treeway and Grumble Volcano involve skipping checkpoints using areas that were never meant to be accessed by racers.
- The Mushroom Gorge Ultra Shortcut is caused by a strange physics glitch to do with the bouncy mushrooms (kinoko.brres). If a player performs a trick on one of these bouncy mushrooms, then the game's physics engine will attempt to push the character forwards; if there is a sloped wall in the way (as is the case with this track), then the character is forced upwards instead. Using this method, it is possible to land on the other side of the map outside the cave, and as the end of the cave is the location of the final key checkpoint, a lap will count if this is triggered.
- Mario Circuit and GCN Peach Beach both abuse an area of the physics engine used when a player comes in contact with a solid object. In the case of both of these tracks, the object is a tree, but whenever a player "wallclips" the edge of anything solid with a wall KCL value at any great speed, there is a chance that they will be thrown into the air – often giving enough height to reach over invisible walls and skip areas of the track.
- In the case of Coconut Mall, there are several ways to reach the glitch zone. The most known way involves the character attempting to touch two invisible walls at the same time and being pushed through one of them, clipping the player out of bounds.
- Wario's Gold Mine is glitched because the start line checkpoint is not extended outwards enough for the game to realize that you have traveled backwards across it. The infamous pipe bounce through the road works because the road itself has clockwise culling (meaning that only the top side is solid) to save space in the collision file. The non-pipe bounce method results from a glitchy respawn position that allows players to go backwards into the cave to hit the final key checkpoint and then complete the lap.
- Maple Treeway has an out of bounds area that players can use to skip the first key checkpoint altogether, thus allowing the shortcut after the cannon which normally would not count the lap to do so.
- By allowing access to a rock next to the start line, it is possible on Grumble Volcano to drive in an area outside of checkpoint coverage. When you loop back around, the game will assume that a lap has been completed normally and count the lap.
- Rainbow Road's is possibly the strangest one yet, as it has a version that can only be performed in Wi-Fi Mode, and you need to be registered as Player 7 or above in the room you are in. Put a Fake Item Box near the start line, get hit by it and fall beyond the finish line (do NOT cross the checkpoint). If you get it to work. you will respawn behind the line as 1st place. Drive to the beginning of the U-turn and then back, and trigger the lap.
- Rainbow Road also has another Ultra Shortcut possible on Time Trials. Drive forward until you are at the initial downwards slope and the clip the wall on the side that appears to be on your left when you start the race, then use a Mushroom to go forward to the part where you are aligned with the ramps at the end. Use another Mushroom to shoot off and then land, and finish the lap.
How to Avoid Ultra Shortcuts in Custom Tracks
On the KCL side of things, make sure that your track is properly surrounded by either invisible walls, fall boundaries or ideally both. Make sure to also pay close attention to the KMP file and be sure to test your track thoroughly before releasing it.
A commonly used solution is to place the first and/or last key checkpoint near the lap counter. A close first key checkpoint will decrease the risk of a player leaving between the lap counter and this checkpoint, while moving the last checkpoints to the lap counter may also decrease the room from where a player can leave the track due to the 95% rule. It is strongly advised to keep enough space between checkpoints. The player's location within the checkpoint regions is only updated 60 times per second, and if two checkpoints are too close together, this check may not happen in this area and the game assumes that the player has skipped this checkpoint. 500 units is recommended.