R-Type

R-Type is set in the middle of 22nd century, and the player flies a futuristic fighter craft called the R-9a "Arrowhead", named for its shape, and because it is the ninth model in the 'R' series of fighter craft (but it is the first of the series to actually be used in combat; the previous models were all prototypes). The mission is to 'blast off and strike the evil Bydo Empire'. The R- in the series title originally stood for "ray", as in a ray of light. It was a reference to the many different types of ray-like weapons in the first R-Type. This was later retconned in R-Type Final to refer specifically to the production code as well as a term of endearment for the player fighter craft, the "Round Canopy".

Another theory suggests that "R-Type" refers to Bydo as r-strategists in r/K selection theory.