In the first volume, written in 1963, Simon Tregarth travels from America to Estcarp, on the Witch World, using the Siege Perilous, which sends people to the world that best fits them. There he discovers magic powers, and plays a leading role in a war against high-tech invaders from a third world.
After one sequel, the focus moved to Simon's children, who crossed the eastern mountains to the land from where the Mage Species had come, and many old powers slept for good or ill.
Norton also wrote books set on the continent across the sea, with little overt connection with the early volumes beyond the setting. Many of the later books were written in collaboration with fans of the original.
Tropes from Witch World:
- Attack! Attack! Attack!: Kolder drones do this, due to being completely mindless. The first time he fights them, Simon is disturbed by the fact they apparently have no idea how to defend themselves.
- Arranged Marriage: Common.
- In the first book, Loyse is ax-wedded (basically, a proxy wedding) to the Duke of Karsten for her wealth and relation to the old nobility. It takes her until the second book to actually meet him, since she flees Verlaine immediately after.
- The narrator of Year of the Unicorn is one of the virgins given to Were-Riders as payment for their help agains Alizon raiders.
- In The Crystal Gryphon alternating narrators Kerovan and Joisan were married at the age of 8, to strengthen Kerovan's inheritance claim. They were not expected to meet until both become adults — and until Kerovan decides to summon his wife. Even the marriage ceremony was held with a battle axe in his stead, as was the custom. Although Kerovan's odd looks played a role too.
- Balance Between Good and Evil: Which is not maintained — the Good characters are merely aware of it as a fact, that the battle will go on, though the Evil ones really think they can win.
- Casts No Shadow: Gillian in Year Of the Unicorn, after they cast the spell on her.
- Changing of the Guard: The switch from Simon to his children.
- Dreaming of Times Gone By: In Horn Crown, how a character learns the past.
- Gender-Restricted Ability: The Witches are women and shocked by Simon having magic. The Were-Riders are men.
- Home Sweet Home: Most characters crave a place to settle down.
- Mage Species: The Old Race. They have the Power, and they can't be taken over by the Kolder.
- Mama's Baby, Papa's Maybe: Invoked in the Jargoon Pard to explain how he can be his uncle's heir when his uncle has a son.
- Mercy Kill: Jaelithe says killing the Kolder drones is this, as a body being forced to live on with no soul is a Fate Worse than Death.
- More than Mind Control: The second way the Kolder have of controlling people—unlike the mindless drones, these people retain all their wits and simply really want to help the Kolder. They do it to Fulk and Aldis, and try to do it to Simon, but Jaelithe jailbreaks him. When they've captured Simon, a Kolder agent tries to convince him to accept it fully, saying that he is a man of "civilization" (ie, advanced technology, like theirs) and they'd treat him well.
- Our Witches Are Different: Witch World has female Virgin Power witches. They are shocked when Simon Tregarth, a man from another world, has the same powers. (And more shocked when a witch marries him and keeps her powers.)
- People of Hair Color: The people all appear to be white and distinguish themselves by hair.
- Prefers the Illusion: In a short story, the protagonist, severely disfigured and disabled by a magical accident, chooses to live in a permanent dream and forget his harsh reality.
- Switching P.O.V.: In The Crystal Gryphon the odd chapters are told by Kerovan and even — by Joisan, two sides in an Arranged Marriage.
- Talking in Your Dreams: Hilarion first talks to Kaththea like this.
- True Sight: Gillian uses moly to give herself this.
- Virgin Power: The Witches of Estcarp thought magic worked this way. They were wrong.
- War Refugees: Gillian is one herself, among many.
- World Sundering: Twice; once in the backstory, to create the eastern mountain barrier of Estcarp, once in the third volume, to create a southern mountain barrier.
