No, it's compatibility issues. First off, they have to be opposite genders, obviously. Secondly, Pokemon belong to certain breeding groups. Most belong to just one, but some are in two different groups. They're only going to be able to breed with Pokemon within their own breeding group. There's also a "No Eggs" group, or Pokemon that wil not be able to breed at all. The list is filled mostly with Legendaries and Babies.
There are four levels of compatibility:
1) "The two prefer to play with other Pokemon than each other." - This means the Pokemon are somehow incompatible, such as same gender, different egg groups, etc.
2) "They don't seem to like each other much." - This means the Pokemon are different species but compatible, and have the same trainer ID. They'll breed eventually.
3) "The two seem to get along." - This means they're either the same species with the same trainer ID, or they're different species with different IDs. They'll breed more successfully.
4) "The two seem to get along very well." - This means they're the same species and have different trainer IDs, giving them the highest chance of breeding successfully.
The exception to all of this is Ditto, of course. Ditto can breed with any gender, including genderless, and they'll all have level 2 (or 3 if they have different IDs) compatibility with it. Ditto still can't breed with "No Eggs" group, however, and neither can it breed with itself.
For whatever Pokemon you'd like to breed, look them up on www.veekun.com to see which egg group(s) they belong to. Also, if you really want to dig into breeding to figure out how to make crazy awesome little babies, feel free to check out Smogon's gigantic & in-depth breeding guides:
SmokeRulz (Expert) - 8 years ago
Yes you can use smogon DB about breeding.
andibad - 8 years ago
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