The other day, I was wondering about this, and I hope I can put this down and it's understood.

If I were to breed (as an example) an Arab-lined Arab to a Morgan to get a Morab, then breed the Morab to an Arab...would I get a crossbreed or a Morab?

Like...is it possible to breed back to an Arab line again? Kinda like RL, where outside breeds have been added to another to add traits or improvements, but the descendants are not considered crossbreeds, but of the original breed? 

As it currently stands, morab x not a morab would be a crossbreed (according to the crossbreed list in the help pages).

So if a crossbreed was bred to, it'd produce a crossbreed, then all descendants would be the same?

Sorry. Missed this the other day.

If you breed an Arabian to a Morgan, you get a Morab. Next gen, you breed an Arabian to a Morab, you'll get a Morab. 3rd gen, you breed a Morgan to a Morab, you'll get a Morab. 4th gen, you breed an Appaloosa to a Morab, you'll get an Appaloosa x Morab lol

So no. Once you've bred two different breeds together, there's no going back to one of the founding breeds.

Thank you for the answers, you two! 

I don't know what prompted the question; it just popped into my head one day. lol