GSC egg info - Shiny Hue, hidden OT, Crystal moves

[Mark_Eire]

Posting to have a record of some GSC egg investigations I've made playing recently. Perhaps this is already known, but I'd not found the info myself.

Breeding for shinies in Gen 2, you can use Stadium 2 to detect shinies by the Hue of the egg (details as noted on bluemoonfalls).

Using Fëanen's document for Hue calculation (link), I noticed a few Pokémon that would have undetectable shiny egg hues for my Gold TID/OT combination. My plan to trade eggs from Gold to Crystal to change the egg.

1. Turns out eggs have some hidden OT data. Though showing TID of hatch game after a trade, while still an egg Stadium 2 imposed limits on non-OT Pokémon withdrawal until 150 Pokédex. This also applies to eggs 
2. As the hidden egg generation TID is set for eggs, no trading will get around shiny Hue limitations. Hue set on generation, shiny visibility trick for a given Pokémon only on a favourable save file OT/TID.
3. Crystal only egg moves are saved to the egg, so new egg moves are retained for Crystal eggs hatched in Gold/Silver. Probably not many care, but my Gold TID team benefits a few new egg moves.

Hopefully this post is of some use to anyone reading this. Thanks!

Edited April 12, 2023 by Mark_Eire