Breeding for Success in Pokemon X
If you have not already seen my earlier guides on stat distribution and moveset suggestions, then check those out before breeding. This guide will give you tips on how to breed for competitive battling, such as egg moves, IVs, Natures, and Abilities.
Choosing the best Ability
Most of the time, though not all, there is not a best Ability. You want to select the Ability that fits your team, and the Pokémon's role on that team.
If the Pokémon has two different normal Abilities it can have, then the child can have either of these Abilities when it hatches. There is a higher chance that the parent's Ability will be passed on, but it is not guaranteed. The Pokémon can only get the Hidden Ability if the parent has it, so make sure you get that before breeding.
Let's use Heliolisk as an example. Heliolisk is a new Electric/Normal type in Pokémon X and Y. It has access to two normal Abilities, Dry Skin and Sand Veil.
Dry Skin makes the Pokémon recover HP when it is hit by a Water move or when it is raining, but it also makes the Pokémon weak to fire-type moves and reduces HP in the sun. Sand Veil increases Evasion by one level during a sandstorm.
The Hidden Ability is Solar Power, which raises the Pokemon's Special Attack by 1.5 times in the sun, but decreases HP every turn.
The right Ability would depend on if you want the Pokémon on a weather team or not and which one. Dry Skin is good on a Rain team or if you want to switch in on anticipated water attacks, Sand Veil is only useful on a Sand team, and Solar Power is only useful on a Sun team.
Passing Natures on with ease
Natures are very important because they can further change the stats of a Pokémon. Some Natures are neutral and won't change stats at all; usually you want to avoid these. All other Natures will increase one stat by 10% and decrease another by 10%.
You want to pick a Nature that increases one of your most important stats and decrease a less important one. Adamant, for example, is great for Physical Sweepers because it increases Attack and decreases Special Attack.
Natures can be easily bred by having a Pokémon with the right Nature hold an Everstone. This will pass on that Nature to the child. The easiest way to do this is to catch Dittos with the Natures you want and breed them with the Pokémon you want. Ditto can breed with anything so you do not need to find two of the same Pokémon of opposite genders or another Pokémon in their egg group. The egg group determines what Pokémon it can breed with.
Special Egg Moves
Some moves can only be bred into a Pokémon from another Pokémon in its egg group. When you breed two different Pokémon, the child will be the same as the mother, so you will want to have a female of the Pokémon you want to breed. After that, you can get a male that knows the move you want to breed and make sure it is in the egg group.
For example, Tyranitar can only learn Dragon Dance by breeding with another Pokémon that knows Dragon Dance. Haxorus is a Pokémon that is can breed with and it learns Dragon Dance by leveling, so breed a male Haxorus tha knows Dragon Dance with a female Tyranitar. The resulting child will hatch with the move Dragon Dance.
Females can also pass on egg moves now, so after you breed the move, you can breed it with a ditto or with anything else it is compatible with to get more with the egg move. This is useful if you need to breed again for a Nature, Ability, or different IVs.
Getting the best IVs
IVs stand for Inherited Values, which are similar to EVs, effort values. Both determine the growth rate of stats. EVs are trained through Super Training or battling Pokémon. I did a guide on that, which you should check out here.
IVs cannot be changed--they are set when the Pokémon is hatched. This means that you should save IV for last in terms of breeding. You can keep breeding until you have one that you want, but there is an easier way. If your Pokémon has good IVs, you can pass one to the child by having it hold a Power item. You can only get these items by using Battle Points that you get from the Battle Maison in Kiloude City after you've beaten the Elite 4 for the first time.
These items can be identified by having Power at the beginning of the name, promotes a certain stat, and lowers Speed when held. The Power Band, for example, will pass on the Special Defense stat to the child. This way you can pass on the best stats to the children and have the best Pokémon you can.
You can check the IVs by going to an NPC in the Pokémon Center in Kiloude City. He stands still to the left as you enter. He will tell you what the overall potential, which is IV, of your Pokémon is, then say what stat has the highest potential. If you have multiple stats that are the highest, he will list those after. If he says, "Stats like those... They simply can't be beat!", then they are as high as they can go. If your Pokémon has a really low stat, he will comment on it after.
I hope this guide has taught you everything you need to breed the best Pokémon you can. My weekly Spotlight Pokémon articles will start to include breeding tips when relevant, so be on the lookout for those. If you have any questions about breeding or specific Pokémon, just ask in the comments.