Missingno.sav

*ZZAZZ has released a full walkthrough of this event, which has much of the same information as this page. If you would rather hear this from ZZAZZ himself, go here.*

Missingno.sav was a save file for English Pokémon Blue that contained the 2017 April Fools Event. It had six rooms, seven achievements, and one Key Item, 4F. In the file, MissingNo. tries to take revenge on the player for what happened last year. A full fan-made disassembly of the save file exists here, which was referenced in the 2018 event's Eastern Encampment.

## Red's Room

### Music

Rocket Hideout

When the player loads the save file, they are spawned on the same tile you would normally start the game on. After a monologue by MissingNo., the player is trapped in the room by glitch tiles. To escape, they must use a walk-through-walls cheat. After the glitch wall replaces it, the SNES is still able to be interacted with. The PC is too, but there is nothing inside.

### Text

Upon entering the room (loading the save):

```
   Greetings.
   So you're back!

   It is so nice to
   see you again.

   I was defeated a
   year ago, but
   this time, I won't
   give up easily.

   In fact, I won't
   even let you do
   anything!

```

MissingNo. places a wall of glitch tiles in front of Red, and the music starts.

```
   You see?
   Now you're stuck!

   Just give up!
   You can't do
   anything here!

   Surely there's no
   way for you to
   go through walls!
   See you later!

```

## Guardhouse

### Achievements

I'm good on my own

Going down Red's stairs leads to the Guardhouse. MissingNo. threatens to crash the game if you use walk-through-walls again (this holds true for the rest of the save as long as the map script is active) and creates another wall to trap the player. Also trapped is the guardhouse's guard, who offers to sell a RIVAL's for ₽999999. Using an infinite money code will allow the player to buy the item, and it can be used to walk through the wall. If the player instead edits their coordinates, removes the wall, or uses any other solution that doesn't require an item, they will get the "I'm good on my own" achievement.

### Text

Upon entering the room:

```
   What? How did you
   escape?

   Ah, you and your
   debugging tools
   these days...

   Let me try that
   again.

   But this time, I
   will crash the
   game if I see any
   WTW cheating!

```

Guard:

```
   Have I got a deal
   just for you!

   You can have this
   swell glitch item
   for just ₽999999!

```

If the player says No:

```
   You don't want it?
   Okay then.

```

If the player says Yes, but doesn't have enough money:

```
   Oops! you can't
   afford it.

   That's really
   unfortunate.

   If only you had
   a way to get an
   infinite amount
   of money...

```

If the player says Yes otherwise:

```
   Sold! Here's your
   glitch item!

   [name] received
   RIVAL's!

```

## Bruno's Room

### Achievements

Top Percentage

In this room the player must beat Bruno/???'s level 255 Ghost MissingNo. (who only knows a low accuracy glitch move called PWNZORD) with a level 1 Magikarp named 'lol'. Solutions included editing the MissingNo.'s health to zero or giving it every status, among others. Bruno will give you 4F, with one subroutine called 'ClearDoor', after you beat him. The subroutine can be used to leave the room. If the player's Magikarp is at least level 10 be the time they leave this room, they will get the 'Top Percentage' achievement. This can be done by talking to Bruno again after beating him to fight him again, giving yourself rare candies, or editing Magikarp's EXP or level directly.

### Text

Upon entering the room, after walking up:

```
   What? You escaped
   again?

```

If the player has at least one item:

```
   So now, let's see
   how you will
   handle THIS
   situation!

```

Otherwise:

```
   And you didn't
   even need any
   items to do so?

   Looks like I'm
   dealing with a
   professional!

```

Bruno:

```
   ... ... ... ...
   ... ... ... ...

```

Bruno fights the player (using Red's sprite, the name ???, and the Gym Leader theme) with a level 255 Ghost MissingNo.

After beating him for the first time:

```
   ...
   ...

   What?
   What happened?

   The last thing I
   remember was a
   ZAPDOS cry...

   And after that,
   everything went
   black...

   I also found this
   really strange
   item in my room.

   I have no idea
   what it does,
   maybe you can
   make some use out
   of it...

   [name] received
   4F!

```

Using 4F for the first time:

```
   Loading...

   Welcome.
   I am 4F.

   I am 8F's younger
   cousin.

   I am here to
   help you.

   I will give you
   access to the
   game's internal
   structures.

   With me, you can
   bend the game to
   your own will.

```

## The Forest

The Forest as it appears with TileBlockPtr 0x69EF (left) and 0x69DF (right)

### Achievements

0x Up Presses

Entering this room gives 4F the ability to change the TileBlockPtr (D52C) between 0x69EF and 0x69DF. Subtracting the TileBlockPtr by 0x10 has the same effect as subtracting the ID of every block in the map by 1. The blockdata stored in the save file for this map includes chunks of Viridian Forest on the east and south sides. Solving the maze without pressing the Up button (which is fairly easy if you know what you're doing, just be careful not to go below the ladder) will give the player the '0x Up Presses' achievement.

## League Gate

### Achievements

Guard Skip, Pokédex flags are weird

This room contains a guard who will stop any player who walks within the two tiles in front of him to tell them that a Chansey is required in order to pass through the door, because of "rules". 4F's new ''GivePokemon" subroutine will help you to obtain a Chansey. Two achievements are obtainable in this room. 'Guard Skip' is given if you bypass the guard entirely; either by editing the map, using 4F's TileBlockPtr, changing your coordinates, or some other method. 'Pokédex flags are weird' is given for seeing more Pokémon than you've owned. Giving yourself a glitch Pokémon will accomplish this (since their 'own' flags are the same as other Pokémon's 'seen' flags), but you could also edit the Pokédex flags directly or use an instant encounter code.

### Text

Guard, if the player doesn't have a Chansey (or he is talked to):

```
   To continue past
   here, you need to
   own a CHANSEY.

   Sorry!
   Rules are rules!

```

## Darkness

### Achievements

Did I getcha?

This is the last room of the save. MissingNo. decides that the player is too close to defeating them, and traps them in an empty room with nothing to do. 4F unlocks a new subroutine in this room to "clear" the save file (the save isn't actually erased), and using that subroutine will play the Hall of Fame sequence and give the player their password. If the player changes the TileBlockPtr and walks out of bounds, they will get the 'Did I getcha?' achievement.

### Text

Upon entering the room:

```
   Enough already!

   All of this was
   fun and all, but
   this time, you're
   trapped for good!

   No warps. No NPCs.
   No signs.

   Complete darkness.
   Enjoy your stay.

```

Using 4F:

```
   Hahaha!
   Even 4F won't help
   you now!

   A new subroutine
   was unlocked just
   now, but I doubt
   it would help.

   Let's see what
   it is...

   The new function
   is... ClearSAV.

   ... ...
   ... ...

   Wait... If you
   clear the save...

   Will I get
   removed too?

```

If the player changes the TileBlockPtr and walks up or down:

```
   Oh...
   You don't want to
   erase the save?

   ... Yes!
   Exactly!

   This definitely
   wouldn't work!
   It's too easy to
   be true!

   You should try
   going out of
   bounds instead!

   Try going to the
   side! Trust me!

```

Player is 2 steps from map's edge:

```
   Yes! Only a few
   more steps!

   Look, I think I
   see a PIKABLU
   hiding over here!

```