As a funny note, it started out as Duke Nuk em, but was quickly released as Duke Nuk um because of a Captain Planet and the Planeteers character with the "Duke Nukem" name. The Duke Nukem series: not counting spin-offs, Duke Nukem, Duke Nukem II, Duke Nukem 3D and Duke Nukem Forever.The numbers don't indicate proper order at all (for example, the "1" in Battlefield 1 stands for World War I), and there's bound to be a lot of confusion over the two games set in The Vietnam War now.