Null Egg

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

This is a glitch that was originally thought to be a random occurrence at the end of 2-2, where some people would get a strange crash without reason. That was until ArneTheGreat discovered that it had something to do with the rat carrying an egg. He looked into it further and the first truly broken category was born: Magical Journey
The following video explains the sprite ID slots regarding the Null Egg and also demonstrates the different uses of it.

Magical Journey

Null Egg Demonstration

How To Get The Null Egg

• In 2-2, enter the final screen with 6 eggs and do not use any.
• Near the end of the level, grab the rat as it jumps out of it's hole and spit it into the green Shy Guy.
• Next, 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.
• Then, 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.
• Finally, scroll the screen up and jump, then complete the level as normal. 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 Null Egg is not setup properly.
  

Fast Null Egg Setup

Null Egg Game Crash

Even Faster Setup. Skip to 15:45

How To Get The Boss Key Sprite

• After getting the Null Egg in 2-2, re-enter 1-8 and 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 trick save corruption which makes the run even faster). Regardless, these eggs will be used for the upcoming levels.
• You can use your remaining eggs to throw at the 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 tonguing and 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 the trick won't work.
• Once you complete the boss fight, the Boss Key sprite will replace the Null Egg 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.

Tutorial/Recommended Strats For All Levels

1-8 Salvo Re-fight Demonstration

Save File Corruption

Doing specific things in 3-1 can corrupt your save file data because of the Boss Key sprite and sometimes it can unlock arbitrary levels, though, it's usually levels in World 6.
The category Any% Beat Bowser (Any% No ACE) was created as a result of this discovery.

Any% No ACE Tutorial (2-2 to 3-1 + Save Corruption)

Any% No ACE Info. (2-8 + 3-1) [See The 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 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. 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% Speedruns

6-4 Null Egg

The next video shows how to get a Null Egg in 6-4. While harder than in 2-2 it is possible and unlike in 3-6 this is actually a little bit faster in an IL run, since it can skip a large portion of the room right before the boss where you normally do a Lava Skip (or take the log).

6-4 IL Null Egg route IDEA
https://www.youtube.com/watch?v=GAVquE4jNwI

6-4 IL Speedrun (w/ Null Egg)
https://www.youtube.com/watch?v=mzaYuIm2jKQ

Script

Head over to the DLC page to find useful tools that will help you a lot learning Null Egg specific stuff.