An Egg Move is a move that a Pokémon can learn by breeding, usually where the male parent knows the move that the female parent’s species is capable of learning as an Egg Move, since Eggs are usually of the female Pokémon’s species. In Generation VI and beyond, female Pokémon will also pass down any Egg Moves they know to their offspring, allowing even greater possibilities and combinations of Egg Moves.
This can result in getting some interesting or powerful moves on a Pokémon that couldn’t otherwise learn it, or at least some various situational moves.
If both the male and female Pokémon know a move that the offspring can learn via leveling up, the offspring will start with that move. That, however, is not considered to be an Egg Move, as it’s just a part of the breeding mechanics. An Egg Move is usually a move that the Pokémon is not capable of learning through other means (although this is not always the case), and it also requires only the male Pokémon to know the move.
You can find all of the Egg Moves a Pokémon species can possibly know by visiting the Marriland Pokédex and checking out the Egg Moves section of the Pokémon’s learned moves. It will show possible Egg Moves even for evolved Pokémon, though keep in mind that those moves are learned in its earliest form rather than its evolved form.
Chain Breeding for Egg Moves
Some Pokémon have Egg Moves listed, but have no direct compatible parent that learns those moves. Since Pokémon have to be in the same Egg Group in order to breed and thus pass along an Egg Move, sometimes you’ll need to undergo a process known as chain breeding in order to get Egg Moves from a distant Egg Group onto a Pokémon.
Let’s say a Pokémon needs to learn Move A as an Egg Move. It is in the Dragon Egg Group. There are no Pokémon in the Dragon Egg Group that learn Move A by leveling up, but there is a Pokémon in the Water 1 Egg Group that does, although there are no Pokémon in both the Dragon Egg Group and the Water 1 Egg Group that can learn the move.
You would then need to find a Pokémon that can learn Move A as an Egg Move in, say, both the Water 1 and Monster Egg Groups and then pass it to that, then breed that move to a Pokémon in the Monster and Dragon Egg Group, and then breed that with the Pokémon you want the Egg Move on.
It’s a bit of a convoluted process, but there are some Egg Moves that can only be gotten through chain breeding.
Relearning Egg Moves
Starting in Pokémon X and Y, and continuing through Generation VI and beyond, Pokémon are able to “relearn” Egg Moves via move relearning services such as the Move Reminder. These Egg Moves must have been passed down to the Pokémon when it was hatched, so this method cannot be used to learn Egg Moves that the Pokémon didn’t originally know.
However, this can still be useful to preserve up to four Egg Moves as options that can be learned again at essentially any time, and provides a good incentive for Pokémon breeders to get multiple Egg Moves on their Pokémon. Even if these moves are forgotten, they can be taught again via the respective service.
In earlier games, though, once an Egg Move is forgotten by a Pokémon, there is no way for it to learn that move again. You’d have to breed another Pokémon with that Egg Move.
Egg Moves in the Wild
In Pokémon Omega Ruby and Alpha Sapphire, the DexNav feature allows you to target specific Pokémon to encounter in the overworld. Some of these overworld Pokémon may even have Egg Moves learned naturally, without any breeding required. The greater the number of Pokémon you’ve knocked out with the DexNav, the greater chances you’ll have of it having an Egg Move.
Similarly, in Pokémon Sword and Shield, certain Pokémon visible in the overworld may have a yellow glow, and the chance of this happens increases as you knock out more of that species of Pokémon. Rarely, these Pokémon may have an Egg Move learned naturally, again without the requirement of breeding for it.
Learning Egg Moves (Gen VIII+)
In Pokémon Sword and Shield, Egg Moves are even easier to learn than ever, with a new mechanic introduced that gives the possibility of Pokémon learning Egg Moves without breeding.
If you leave two Pokémon of the same species in the Pokémon Nursery, regardless of their gender, and one of those Pokémon knows one or more Egg Moves, you can walk around or ride around on your bicycle for a minute or two and then pick up the Pokémon that didn’t know those moves. There’s a good chance that it will have learned those moves when you pick it up from the Nursery (if not, just put it back in the Nursery and run around for a bit longer, as if you’re waiting for an Egg to be produced, as it takes time).
You’ll need to make sure that the Pokémon you want the Egg Move(s) on has empty move slots, otherwise it won’t learn the move, but thankfully it is extremely easy to use the Move Deleter functionality in any Pokémon Center to make room for any moves.
This can be a great way to pass several different Egg Moves onto different Pokémon of the same species, and then getting all of those Egg Moves onto a single Pokémon of that species and using that one for breeding to easily get all of the desired Egg Moves instead of having to breed each Pokémon to get an offspring knowing Move A and Move B, then breeding a female of that species with a compatible Pokémon that knows Move C, and so on.