Bad Egg
?????????? | ????? | ! | Abnormal Pokémon | Bad Egg | Enigma Berry (Generation III) | Error! | Error codes (Generations I and II) | Error traps for damaged save data | Error traps to prevent impossible progress | Event data debugging messages | Instant victory effect (Generation II) | Mystery Zone | N/A | Pokégear instruction booklet trap | Rhydon trap | Special (location) | This Game Pak is designed only for use on the Game Boy Color. | This Pokémon cannot be traded.
This article is a summary page for different variations of a glitches, etc. when talked about as a whole.
|
The term "Bad EGG" in the Generation III Pokémon games and later "Bad Egg" in the Generation IV games, refers to an error handler which was presumably, originally used by the game developers to refer to individual Pokémon (as eggs) with stats which do not conform to the original defined data of that Pokémon for when it should hatch such as the individual values, base stats and ability of that Pokémon. For example, of an egg which was illegitimately (without writing to the checksum) given an excessively large attack stat for when it should hatch. Normally, when a player recieves an egg, the game should write to the checksum by using an algorithm to calculate the total of unencrypted Pokémon data. If the game later considers the checksum to be invalid, i.e. if it is greater or lower than a possible value based on XOR calculations (perhaps if the EV total is greater than 510) the game will interpret the Egg as a "Bad Egg".
However, since after Generation II Pokémon in one sense are simply eggs with an additional byte with a value of 01 (ON) it is possible that a hatched Pokémon would also be taken by the game as a 'Bad Egg', which could suggest that the game developers did not expect other game developers to accidentally invalidate the checksum of a gift Pokémon with variable characteristics for example.
Like ordinary eggs, Bad Eggs under normal circumstances can never be released and when the player attempts to view one's summary screen the game will not give the details of the Pokémon (if it was not an egg) but rather, the game would display another interface which suggests how long it would be until the egg hatches.
In non handheld Pokémon games
It is notable that the error handler "Bad EGG", or "Bad Egg" is still used in Pokémon Colosseum, Pokémon XD and Pokémon Battle Revolution; despite the fact that eggs alone are normally unobtainable within these games. For this reason, it could be suggested that it is used simply so that the game does not crash. Furthermore, Eggs and Bad Eggs even use their own unique models and strangely appear as eggs with brown spots instead of the usual green.
In Generation IV
Unlike in the third generation of Pokémon games, for unknown reasons Bad Eggs actually have their own defined identifier of 495 (1EF) in the species byte. Such a 'Pokémon' if encountered in the wild by has Splash as its only move but it has no defined data for its cry, hence it uses the cry of a Bulbasaur (the first valid Pokémon in the species byte).