MissingNo.

The five forms of MissingNo.

### Index (hex)

1F, 20, 32, 34, 38, 3D, 3E, 3F, 43, 44, 45, 4F, 50, 51, 56, 57, 5E, 5F, 73, 79, 7A, 7F, 86, 87, 89, 8C, 92, 9C, 9F, A0, A1, A2, AC, AE, AF, B5, B6, B7, B8

### Index (dec)

31, 32, 50, 52, 56, 61, 62, 63, 67, 68, 69, 79, 80, 81, 86, 87, 94, 95, 115, 121, 122, 127, 134, 135, 137, 140, 146, 156, 159, 160, 161, 162, 172, 174, 175, 181, 182, 183, 184

### Back sprite source pointer

0x8F37

**Missing Number** (Japanese: **けつばん** *Ketsuban*, lit. "Missing Number"), referred to by Nintendo of America as **MissingNo.**, and appearing in-game as **MISSINGNO.** refers to a group of glitch Pokémon that act as fillers for vacant slots. For each version, there are 39 separate MissingNo. slots. Three particular examples also serve a specific purpose throughout the game; as the Kabutops Fossil, the Aerodactyl Fossil, and Pokémon Tower Ghost.

Most of the data pertaining to MissingNo. is clearly glitched and unintentional (and there is no error prevention, unlike for example the placeholder sprite loaded in place for the Generation III glitch Pokémon ??????????) and in itself MissingNo. is not a legitimate Pokémon, but curiously some data like nine of the MissingNo. cries are leftover development remnants. During the development of Pokémon Red, Green and Blue, the index numbers of many of the MissingNo. were instead occupied by unreleased Pokémon, but in the final games the leftover cries are the only hints that cut Pokémon ever existed.

The index numbers for "MissingNo." entries appear in between valid Pokémon, and combined they add up to 190 entries (151 valid Pokémon+39 MissingNo.). This was in fact an early number for the total number of Pokémon according to the 2020 Pokémon Blue source code leak, but it is also known that in total Game Freak have created even more draft designs of Pokémon/or any other monster designs pertaining to the Capsule Monsters pitch than 190, just not necessarily ever programmed into the game. One MissingNo. that doesn't exist in the final games may have also been replaced with Mew (hence hypothetically at this point in development, there were 40 MissingNo.; not 39). According to Iwata Asks (Pokémon HeartGold and SoulSilver), Mew was programmed into the game near the very end, after debugging features were removed to make space. At some point (as found by asset leaks) a cut Pokémon actually occupied Mew's index number (0x15, dec:21) as Omega.

While technically there can be 256 indexed species (2^8 entries in one byte), the other glitch Pokémon only exist after Victreebel (190) with names not programmed into the game but extrapolated from unrelated data beyond MonsterNames encoded as if they were Pokémon names. ('M (00)/3TRAINERPOKé₽ (00) can be interpreted as both the index 256 or index 0 Pokémon).

All MissingNo. are Pokédex number (family) 0, which is coincidentally the same Pokédex number as 'M (00). However, only (English versions) 'M (00)/3TRAINERPOKé₽ (00) are index number 0 (when distinguished from the Pokédex number, and some index number 0 Pokémon have non-0 Pokédex numbers, such as 176 for 3TRAINERPOKé₽).

MissingNo. is among the most well-known Pokémon glitches in the English player base, likely because it can be encountered through simple glitches and provide a means to duplicate items (see glitch Pokédex flags). It also typically but not always, appears identical to 'M (00).

## Misconceptions

This is a list of misconceptions about MissingNo.

### Its index numbers

Many people incorrectly state that MissingNo. occupies index numbers 0x98 to 0xBE (152 to 190). That is NOT true whatsoever, because MissingNo.'s index numbers are actually between 1 and 190; its index numbers are 1F, 20, 32, 34, 38, 3D, 3E, 3F, 43, 44, 45, 4F, 50, 51, 56, 57, 5E, 5F, 73, 79, 7A, 7F, 86, 87, 89, 8C, 92, 9C, 9F, A0, A1, A2, AC, AE, AF, B5, B6, B7, and B8.

### It's dangerous, hazardous

Nintendo and some players incorrectly believe that MissingNo. is very harmful to your save file, that it erases it. That is NOT true whatsoever, it only corrupts your hall of fame data, the only side effect other than that and the fact it affects your sixth item's quantity is that for some reason it autosaves your game.