6th Gen I don't know where this question goes. o_o;

[Venonat in Space]

Got Japanese Snivy (level 19) and American/English Ditto (level 90) off the GTS on Omega Ruby. The Snivy knows leaf tornado. If I breed them, and they just *happen* to be *not* legit, will they produce a bad egg in gen 6? Further more idk if they're legit or not, but what WILL happen in gen 6? I'm scared to know. Hence why i'm asking here.

Please mods, if this is in the wrong place, feel free to move the thread.

 

[Nah]

If Snivy knowing Leaf Tornado is your sole concern, it learns Leaf Tornado at level 16 in all 3 generations it's been in so far, so there's nothing unusual in regards to that.

Or is there something else that concerns you about the Snivy and the Ditto?

 

[Venonat in Space]

If Snivy knowing Leaf Tornado is your sole concern, it learns Leaf Tornado at level 16 in all 3 generations it's been in so far, so there's nothing unusual in regards to that.

Or is there something else that concerns you about the Snivy and the Ditto?

I just want to know what happens if you breed a NON-legit Pokemon and what happens to the NON-legit egg. That's all.

 

[Nah]

I don't actually know much about Bad Eggs myself, but as far as I know you usually have to make use of Action Replay type devices or really glitch out your game in order for a Bad Egg to appear. People have long used illegal Dittos (or clones of illegal Dittos) for breeding purposes and I've not heard of people having problems from that. If there is something very obviously wrong with either of them (moves they cannot learn under any circumstances, impossible meet/catch locations, abilities they don't get, the OT being a known hack source, etc) then you might not want to make use of them, but otherwise you're probably ok?

 

[Megan]

Bad eggs have been around for about the same time breeding exists. In the earlier games there was usually a Pokemon slot dedicated to the "egg" so as to make it possible to the player to carry eggs from breeding around. This specific egg was never obtainable through normal way, only popping up when something went terribly wrong (bugs/glitches/messing with memory in terrible ways).

I've not heard much about bad eggs in newer generations. I think a weird exploit in gen 6 that allowed you to get basically any Pokemon you wanted. That could technically result in some really messed up data. But that can only happens to the person who put it into their game. But you didn't create them yourself and instead got them traded, meaning it's not your case.

If you got two Pokemon that are not legit (as in: "not obtainable in this form in legal ways") then it's because the game still sees them as legal. There's some arbitrary testing in the background and if it could be traded at all that means it passed that test.
Breeding a Pokemon means creating a new Pokemon using stuff from the ones you used like the species and what moves they know. Snivy and Ditto are legit species and Leaf Tornado is a legit move that exists. In that regard there is nothing that can go wrong.