Obviously, Blacula is a blaxploitation film.  It is about a vampire of African descent. The movie is all right at first, but then it goes stupid. The detective knows he is after a vampire, and he knows all the rules about killing vampires with sun exposure or a wooden stake through the heart, and he knows that a cross will make a vampire cringe. But when he goes to the place where he suspects that Blacula keeps his coffin, he goes with cops who are armed with nothing but pistols, which are ineffective. So cops get killed left and right. But the detective has a cross for himself, of course. Oh well, it could have been worse. Blacula could have been played by Christopher Lee in blackface.