Null Egg

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Individual Level Strats

World 2

2-3
2-4
2-5
2-6
2-7
2-8


World 3

3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8


World 4

4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8


World 5

5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8


World 6

6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8


Introduction

  • The Null Egg was originally thought to be a random occurrence at the end of 2-2 that would cause the game to crash. That was until ArneTheGreat looked into it further and discovered that the crashes were caused by a rat carrying an egg.
  • If you grab the egg from the rat (without destroying him) and he despawns, the egg will also despawn because it is tied to the rat's sprite. When this happens, it creates an open sprite slot in your egg inventory - a null egg. This slot is subsequently filled by the next sprite that loads in, even if its a non-egg sprite like an enemy or collectible. Since sprites being loaded into the egg inventory in this way is not supported by the game, it usually results in a crash.
  • After some experimentation, it was figured out that the boss key sprite could be obtained and then used to beat levels soon after they begin. This created the first truly broken/glitched speedrun category Magical Journey.

The following video explains how sprite ID slots work with regards to the Null Egg and also demonstrates the different uses of it.

Magical Journey
Game Crash
Null Egg Demonstration


Getting The Null Egg

This text tutorial corresponds to the video down on the left.
Destroying the enemies in this section is to make sure the correct sprite loads into the open slot in Yoshi's egg inventory.

  • Enter the final screen with 6 eggs and do not use any.
  • Grab the rat as it jumps out of it's hole and spit it into the green Shy Guy.
  • Tongue the Skull Rat and then spit it into the Piranha Plant.
  • Jump and grab the egg that the rat is carrying before it falls down. When the rat despawns, you will have the null egg.
  • Go up the hill and tongue the first rat and spit it into the second.
  • Go back down the hill and follow the rat carrying the egg to the left, up the other hill.
  • Scroll the screen up and jump to load an off-screen rat into the open slot in Yoshi's egg inventory.
  • Complete the level like normal but do not use any eggs or kill the final Piranha Plant.

Keep in mind that the game can crash upon entering the goal ring if the setup is not done properly.

Easy Setup
Faster Setup. (Skip to 15:45)









Getting The Boss Key Sprite

  • After getting the Null Egg in 2-2, re-enter 1-8 to fight Salvo to get the boss key sprite into your egg inventory.
  • You want to end the fight with 2 eggs + the Null egg if you're running the Beat Bowser category and 3 eggs if you're running Magical Journey. (Both categories are more or less the same except Beat Bowser uses the save corruption trick to makes the run even faster). These eggs will be used for upcoming levels.
  • You can use your remaining eggs to throw at the water spitting fish in the second room, the red switch in the room after and one for the boss.
  • Throw one egg at Salvo and then finish the fight by spitting the small slimes into him.
  • Do not tongue and catch the egg after you throw it, otherwise it will mess up the sprite ID slots and you won't be able to get the boss key.
  • Once you complete the boss fight, you will have the boss key in your egg inventory which will allow you to beat every level thereafter really quickly.

In theory, it would be faster to use the boss explosion sprite rather than the boss key sprite but the game crashes in many levels when doing this because the level gets completed before being properly loaded.

Null Egg Tutorial For All Levels
1-8 Salvo Re-fight Demonstration









Save File Corruption

This trick allows you to unlock 6-8 after 3-1 by corrupting your save data. The Any% Beat Bowser category was created as a result to differentiate it from Magical Journey.

  • You have to use file 1, otherwise it won't work. Up to this point, the run is the same as Magical Journey.
  • When you enter 2-8, push against the pipe to ensure you enter 3-1 with the same sub-pixel position (.FF) every time.
  • Upon entering 3-1, hold right before the level intro begins and press B three times to ensure you get the same value for the sun timer every time.
  • Fall into the first pit and hold left. You have 19 frames to turn left after falling and each frame produces a different result. Some frames do nothing and some will unlock any given world 6 level, excluding 6-1. There are 2 frames which unlock 6-8 so it's basically random for real-time speedruns.
  • After you complete 3-1, reset the console, select file 1 and hope that you got the right frame to unlock 6-8 to finish the run.
Any% Beat Bowser Tutorial
2-8 and 3-1 Info. (See Video Description)








Further Information

The position of the boss key sprite affects how quickly a level gets completed. Compared to having 3 eggs in front of the key:

  • Having 2 eggs loses 9 frames per level.
  • 1 egg loses 47 frames.
  • 0 eggs loses 49 frames.

The Boss Key also affects a few levels differently depending on the version. From fastest to slowest overall version it's:

  • J1.0 > J1.2 > J1.1 > U1.1 > PAL > U1.0

The Null Egg In Other Levels

3-6 Null Egg

The Null Egg can also be acquired in 3-6. A Screen Transition sprite can then replace the Null Egg to trigger a 1-1 Warp to complete the level. Unfortunately for the IL run of this level, the 1-1 Warp is slower than doing the level normally, however, the 3-6 Null Egg can be used in 100% No Restrictions to save multiple minutes.

3-6 Any% Speedrun Using The Null Egg
How The 3-6 Null Egg Can Save Time In 100%









6-4 Null Egg

The Null Egg can even acquired in 6-4! While it is harder to get than the Null Egg in 2-2, this one actually saves time in an IL run, unlike the one in 3-6, since it allows you to skip most of the room before the boss where you would normally do the Lava Skip (or take the log). A middle-ring replaces the Null Egg and upon dying and respawning, you're placed after the lava section. All you have to do after is fight Tap-Tap.

6-4 Null Egg Demonstration
6-4 Any% Speedrun Using The Null Egg









Extra Help

Head over to the DLC page to find useful tools like Lua with sprite slots and RAM watch that will help a lot to learn and better understand specific Null Egg things.