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no, he never turned ssj3 in the series BUT in dbz raging blast game he turned ssj3 in wat if saga (its not just vegeta turned ssj3 in raging blast BROLY turned ssj3 too ) =D
sorry , but there is no ssj3 vegeta, but there is a ssj4.
No.
Yes.
in your computer
Goku is the person that can turn SSJ3. In fact he is the only person that can turn SSJ3 in dragon ball z. Gotenks can also transform into SSJ3 but i dont know if u can really include fuzed characters, and more recently in the raging blast games vegeta, and Broly can also but they never did in the anime, Although it is kind of logical seeing how Vegeta can go SSJ4 and Broly is the "Legendary Super Saiyan". So can vegeta and broly
they are about the same but goku is a tiny bit stronger but not by much
Episode 230 Super Saiyan 3?!
episode 214 when hes majin
Vegeta turns super sayian in episode 59 of Dragonball gt
He dosent turn ssj 3 in the series. goku turn ssj3 because he was dead. goku could only turn ssj3 when he was dead, so he lost his time on earth when he was dead on the series. gohan get his potential (mystic/ultimate gohan) and he don't turn ssj, but in gt he is only ssj1,so he doesent turn ssj3.
you need to obtain 20 stars in dragon battle collection, and buy the secret Battle 47 (What-If Stories) - beat this battle to unlock ssj3 vegeta (it is a separate character from vegeta as it is not canon)