Planet of Adventure

A Science Fiction quartet by Jack Vance, featuring the adventures of Adam Reith, a spacer from Earth, who crash-lands on the newly discovered planet Tschai. Tschai is inhabited by four alien species, the Chasch, the Wankh, the Dirdir, and the native Pnume. In addition, surprisingly enough, there is a thriving population of humans, who appear to have been captured and brought to the planet ages ago. Many of the humans work as servants or slaves to the other species, though there are also various independent tribes. The other four species living on Tschai have an uneasy peace between them. Reith must navigate the dangers of the planet and the complex variety of cultures, and he ends up dealing with each species in turn as he tries to find a way to return home.

The four volumes of the series are:
 * The City of the Chasch
 * Servants of the Wankh
 * The Dirdir
 * The Pnume

Tropes in this series:

 * A Child Shall Lead Them: Traz. The nomad tribes' nominal leaders are generally teens or pre-teens (probably so the priests, who are the actual leaders, can have an easier time).
 * Bizarre Sexual Dimorphism: the Dirdir have a complex sexuality. A male will be born with one of twelve different sex organs, females one of fourteen. Each type matches one or more of the others. Mating is complicated by the great secrecy surrounding sex: no-one wants to be "outed" as a particular sex since there are a host of restrictive sexual stereotypes waiting to be applied.
 * Deadly Decadent Court: The Yao.
 * Desert Punk: the first two books, definitely.
 * Dungeon Town: In The Dirdir.
 * Emotionless Girl: Zap 210, heroine of The Pnume.
 * Forgets to Eat: Adam Reith at one point realizes that the reason everybody else is so cranky and tired is that they haven't eaten in two days, and by extension, neither has he.
 * Full Frontal Assault: Ylin-Ylan is one of the Yao, a people with an extraordinarily strict code of pride and etiquette -- imagine the most exacting dictates of Victorian England melded with the complexities of court life in Ancient Japan. When Ylin-Ylan finally loses it over being slighted in love, she turns up at dinner completely naked, holding a gun and a knife: when she gives up on restraint, she goes all the way.
 * Good Old Fisticuffs: Like many Vance heroes, Adam Reith is a skilled hand-to-hand fighter.
 * Horse of a Different Color: The "leap-horses" are the native substitute quadruped. They have heads resembling a horned tapir and exaggeratedly long necks as shown here. As their name implies their motion is more of a bounding motion that a horse-like gait. All in all riding one sounds like a fast-track to lower back problems.
 * Humanity On Trial: Of a sort. Ends with a very angry Reith repeatedly smashing the alien's head against a sidewalk.
 * Humanity Is Superior: although none of the other species seem to think so, Reith tries his best to demonstrate the truth of this.
 * I Have Many Names: Ylin-Ylan.
 * No Periods Period: The Pnumekin (human servants of the Pnume) are given drugs to suppress menstruation and physical development. Zap 210 is cut off from her supply when she falls in with Reith, and the inevitable happens just in time to make an Attempted Rape that much more traumatic.
 * Proud Warrior Race Guy: Traz Onmale.
 * Punch Clock Villain: the hero is once approached by a well-dressed man who introduces himself, informs him that the Assassin's Guild has taken out a contract on him, and asks him to roll up his sleeve. Hilarity Ensues.
 * Recursive Precursors
 * Villainous Glutton: the monstrously obese Aila Woudiver.
 * You Are Number Six: Zap 210.
 * You Didn't Ask Anacho has spent the first two books assuming that Adam Reith is crazy because he claims to have come from some other planet called "Earth". Until Traz mentions that he saw Reith's space boat.