Luke Rhinehart, psychiatrist, bored and unhappy with his life, hits on the idea of using dice to live his life, writing out lists of options and rolling a die to find out which one he'll go with. Sometimes the decision is as trivial as what to eat for breakfast; sometimes the die dictates what role he'll play at a party; sometimes it directs the whole course of his life.
It's utter crap, but occasionally quite enjoyable utter crap, watching as the dice get ever more out of control and Luke's old life spirals ever further down the drain. Rhinehart (a pen name for George Cockroft) cooks up a psychiatric theory for the dicelife based on the idea that it frees multiple repressed selves; I actually found this mildly intriguing and conveniently difficult to argue against, as it effectively sidelines any conventional idea of what truth and morality and personhood is. The apparently arbitrary nature of the decisions the dice make for Luke also lead to some genuinely suspenseful moments.
The one major beef I have with the book - the reason I wouldn't recommend it - is its frankly misogynistic outlook, especially with regards to rape and consent. The first dice decision Luke makes is to go downstairs and rape his neighbour Arlene. Which he does. And Arlene enjoys it, because she's a bored and unsatisfied housewife who needs some excitement in her life. And this is presented as completely OK. And what the fuck, book, have you not heard the words "rape culture"? (Probably not, actually, as this was published in 1969, but it's still shitty.)
There are several other instances where Luke coerces and manipulates women, often vulnerable women, patients and experimental subjects, into sex, and again, this is all completely OK on the basis that they're expressing repressed minority selves.
No. Noooo. Please go away, dice man.