As a thought experiment, the original position is a hypothetical designed to accurately reflect what principles of justice would be manifest in a society premised on free and fair cooperation between citizens, including respect for liberty, and an interest in reciprocity.

In the state of nature, it might be argued that certain persons (the strong and talented) would be able to coerce others (the weak and disabled) by virtue of the fact that the stronger and more talented would fare better in the state of nature. This coercion is sometimes thought to invalidate any contractual arrangement occurring in the state of nature. In the original position, however, representatives of citizens are placed behind a "veil of ignorance", depriving the representatives of information about the individuating characteristics of the citizens they represent. Thus, the representative parties would be unaware of the talents and abilities, ethnicity and gender, religion or belief system of the citizens they represent. As a result, they lack the information with which to threaten their fellows and thus invalidate the social contract they are attempting to agree to.

Rawls specifies that the parties in the original position are concerned only with citizens' share of what he calls primary social goods, which include basic rights as well as economic and social advantages. Rawls also argues that the representatives in the original position would adopt the maximin rule as their principle for evaluating the choices before them. Borrowed from game theory, maximin stands for maximizing the minimum, i.e. making the choice that produces the highest payoff for the least advantaged position. Thus, maximin in the original position represents a formulation of social equality.

In the social contract, citizens in a state of nature contract with each other to establish a state of civil society. For example, in the Lockean state of nature, the parties agree to establish a civil society in which the government has limited powers and the duty to protect the persons and property of citizens. In the original position, the representative parties select principles of justice that are to govern the basic structure of society. Rawls argues that the representative parties in the original position would select two principles of justice:

Recently, Thomas Nagel has elaborated on the concept of original position, arguing that social ethics should be built taking into account the tension between original and actual positions.

The concept of the original position was first used by the Hungarian economist John Harsanyi. Harsanyi claimed that a person in the original position would maximize his or her expected utility, rather than choosing minimax. This led him to endorse utilitarianism.

In Anarchy, State, and Utopia, Robert Nozick argues that, while the original position may be the just starting point, any inequalities derived from that distribution by means of free exchange are equally just, and that any re-distributive tax is an infringement on people's liberty. He also argues that Rawls's application of the maximin rule to the original position is risk aversion taken to its extreme, and is therefore unsuitable even to those behind the veil of ignorance.