If you're a fan of Jack Vance, this may be his best series. If not, this is an excellent introduction to this master of adventure SF and fantasy. In the first ten pages of the first book, Terran explorer Adam Reith's ship is destroyed by mysterious missiles, and he is stranded on the unknown planet Tschai. Tschai has been colonized by several mutually antagonistic alien races; they have imported primitive humans for use as servants; over millenia, several human subspecies have evolved, symbiotic to the various breeds of alien. Our hero gets to spend the next four volumes criss-crossing the planet from one cliff-hanging adventure to another in search of an intact spacecraft that he can buy, borrow, or steal. Gorgeous prose and intricate, fully realized alien cultures raise this above the level of a simple adventure series. Highly recommended.