Egg Group
Egg groups are categories which determine which Pokémon are able to interbreed in Pokémon breeding. A Pokémon may belong to either one or two egg groups.
Egg groups are decided by biological traits, which overall serves to allow Pokémon which are biologically similar to breed. However, there are some oddities which have been noted within egg groups: for example, the Ground egg group's standards are particularly broad, and many illogical pairings can be noted within it, such as Skitty and Wailord.
Breeding chains
Many Pokémon are included in two different egg groups and can form what are known as breeding chains. These link many unrelated Pokémon together, allowing moves that would not normally be accessible to certain Pokémon to be legal, like Heal Bell on Blissey.
TMs are also passed down through breeding from the father. Any move in the father's current moveset that can be learned via TM or egg move will be passed down to the Pokémon hatching from the egg.
Egg groups
This is a list of egg groups by their index number in the games:
- Monster group
- Water 1 group
- Bug group
- Flying group
- Ground group
- Fairy group
- Plant group
- Humanshape group
- Water 3 group
- Mineral group
- Indeterminate group
- Water 2 group
- Ditto
- Dragon group
- No eggs
