The Game of Life and How to Play It is a short New Thought manual that treats existence as a game governed by definite spiritual laws. Shinn opens by rejecting the idea that life is a battle. It is instead a game of giving and receiving whose rules, she argues, are stated plainly in scripture, which she reads as a guide to the workings of the mind.
Her account of the mind has three departments. The subconscious is power without direction, like steam or electricity, carrying out whatever is deeply felt or clearly imagined. The conscious mind perceives the world as it appears, including sickness, poverty, and limitation. The superconscious holds the perfect pattern for each life, the divine design that flashes to a person as an ideal that seems too good to be true.
From this model Shinn derives her central practice: the power of the word. Because words and images externalize, a person is continually making laws for himself by what he says and pictures. The book's many anecdotes describe people who speak a definite affirmation, hold perfect faith, and then act as if they had already received, so that supply appears for every demand.
The middle chapters set out the supporting laws. The law of prosperity ties supply to faith in the spoken word. The law of Karma makes every thought and deed return like a boomerang, balanced by a law of forgiveness that lets a person neutralize past mistakes. Nonresistance is offered as the most powerful stance of all, like water wearing away rock, refusing to fight an evil Shinn regards as illusion. Casting the burden is the practical shortcut for impressing the subconscious with good.
The closing chapters turn to guidance and self-expression. Intuition is the faculty through which a person receives definite leads and acts only when directed. Perfect self-expression, or the divine design, names the unique place each person is meant to fill, combining health, wealth, love, and right work into what Shinn calls the square of life. The book ends with denials and affirmations, the verbal formulas by which the reader is meant to put all of this into daily use.