What is "high-opp"

High-Opp is a science fiction novel written by Frank Herbert between The Dragon in the Sea (1955) and Dune (1965), and published posthumously in 2012. It contains a foreword by Kevin J. Anderson, who co-authored many books in the Dune series with Frank Herbert's son. Brian Herbert.

Though the novel was never published in Herbert's lifetime, some elements of the story were used in his 1977 novel The Dosadi Experiment, sometimes word-for-word.