From the Wikipedia article on Hungarian nationality law:
“The existing Hungarian nationality law dates from 1993. Prior to this date, rules for acquisition and loss of Hungarian citizenship may have been different. With the new Hungarian nationality law, by January 2011, every person who was a Hungarian citizen or is a descendant of a people who was a Hungarian citizen before 1920, and speaks Hungarian may apply to become a Hungarian citizen even if he or she does not live in Hungary.”
“The 2011 Hungarian Citizenship law allows all ethnic Hungarians to apply for simplified naturalisation if they are able to prove knowledge of the Hungarian Language and provide evidence that he or she does indeed have Hungarian ancestry.”