William Sleator, 66, wrote novels geared toward adolescent readers

Moody, psychologically probing, and sometimes terrifying, his work chronicled young people’s passage through all manner of dystopias. It was a fitting juxtaposition of age group and subject matter, for what, after all, is more dystopian than adolescence?

In confronting the grotesque, the menacing, and the outright evil, Mr. Sleator’s protagonists simultaneously confront their own identity and their relationship to their families, especially to brothers and sisters.

His best-known novels include “Interstellar Pig’’ (1984), involving a youth who is drawn into an all-too-real role-playing game - here enters the octopus - in which the losers and their civilizations are destroyed; and “House of Stairs’’ (1974), about teenagers trapped in a malign behavioral experiment.

He was also known for “The Green Futures of Tycho’’ (1981), in which a boy travels forward in time and meets his adult self. The protagonist was named for Mr. Sleator’s youngest brother, Tycho; early on, he often coopted family and friends as characters until, he later said, he had run out of friends in every sense.

William Warner Sleator III was born in Havre de Grace, Md., and was reared in University City, Mo., a St. Louis suburb. His father, William Jr., was a physiologist; his mother, Esther Kaplan Sleator, was a pediatrician who did early research on attention deficit disorder.

Billy, as he was known, grew up amid art, intellectual ferment, and a laissez-faire approach to child rearing that would give helicopter parents the fantods. He captured the milieu in “Oddballs’’ (1993), an autobiographical volume centering on his life with his brothers and sister, Vicky.