The 199 members of the National Assembly will be elected by two methods; 106 will be elected in single-member constituencies by first-past-the-post voting, with the remaining 93 elected from a single nationwide constituency by proportional representation. The electoral threshold is set at 5%, although this is raised to 10% for coalitions of two parties and 15% for coalitions of three or more parties, Seats are allocated using the d’Hondt method.

Sources and Further Reading:

Hungary’s Ruling Party Loses Two-Thirds Majority after By-Election

https://www.wsj.com/articles/hungarys-ruling-party-loses-two-thirds-majority-after-by-election-1424634646

Inter-parliamentary Union

http://archive.ipu.org/parline-e/reports/2141_B.htm

Hungarian General Election: Another Viktory

www.makemeaware.com/another-viktory/