Zelazny's principal precedent is his own first sequence of Amber novels.

Although he introduces new elements, Zelazny mainly elaborates on his previously created universe. Amber/ Chaos/Shadow are not as fully realized as Tolkien's Middle Earth or Stephen R. Donaldson's The Land, for example.

One has the sense that while there may be a good deal of vivid action going on in the foreground, the rest of the stage is decked with rather flimsy and illassorted props dredged from a theatrical company's archives. And yet there are hints, especially in the recent Knight of Shadows (1989), that Zelazny intends to explore the underlying significance of Amber and Chaos in much greater depth. Zelazny's fans may well hope so, for Amber has lost much of its original freshness and excitement.

Another problem with the second series is the fact that thus far Merlin is a less interesting character...