It's quite simple really.
Put your Lucario into the Daycare with a Ditto, then you will get an Egg. Hatch this egg and you will get a Riolu.
Evolve this and you get another Lucario.
No, its impossible. Real Lucario & Lucario Biologist. ~Bolt the lucario
well sorry but lucario can't breed so no.
no but they both can breed
Breed it.
If you have a lucario instead of trying to capture riolu why not breed lucario instead.
Riley on Iron island gives it to you, otherwise you can breed Lucario and ditto in the daycare and get it.
you need to give it lots and lots of happiness
you can breed a lucario with a ditto or go to iron island and get a egg from riley
There isn't one. But you could try to obtain a ditto. And breed the lucario with the ditto until, you find a female. Pokemon Master & Lucario Biologist ~Bolt the lucario
Egg move, so you must breed a Female Lucario with a male Pokemon that knows Crunch (Keep in mind that Riolu cannot breed because it's a Baby Pokemon).
Put in a ditto and lucario in the daycare.
Breed it with a Lucario or a Weavile as a father.