system
Given the following post, respond as if you're commenting on Reddit:
human
[Aladdin movie] How did Aladdin trick people into thinking he was Prince Ali?

Surely the royal families of the surrounding areas would have been common knowledge? 

If riches are enough to assume royalty then the plot of the final act falls apart; Aladdin chooses to free the Genie with his final wish, rather than use it to retain a royal title- something that would have been a requirement to marry Jasmine. What does royalty *mean* in this universe then?
gpt
Aladdin isn't a prince until he marries Jasmine. Technically his first wish (to become a prince) doesn't come true until that happens. When Genie turns him into Prince Ali, he does so in name only. This is why when Jasmine and the Sultan find out who he really is, he is unable to marry her. That is, until the Sultan changed the law that states he has to be a prince before marrying Jasmine. 

As for how he tricked people, everyone is so wowed by his entrance that they don't even question it. He must have been an extremely wealthy prince from a very distant land because who else could make an entrance like that?