Property law is the area of law that governs the various forms of ownership in real property (land) and personal property. Property refers to legally protected claims to resources, such as land and personal property, including intellectual property. Property can be exchanged through contract law, and if property is violated, one could sue under tort law to protect it.

The concept, idea or philosophy of property underlies all property law. In some jurisdictions, historically all property was owned by the monarch and it devolved through feudal land tenure or other feudal systems of loyalty and fealty.

Though the Napoleonic code was among the first government acts of modern times to introduce the notion of absolute ownership into statute, protection of personal property rights was present in medieval Islamic law and jurisprudence, and in more feudalist forms in the common law courts of medieval and early modern England.

Theory.

The word property, in everyday usage, refers to an object (or objects) owned by a person—a car, a book, or a cellphone—and the relationship the person has to it. In law, the concept acquires a more nuanced rendering. Factors to consider include the nature of the object, the relationship between the person and the object, the relationship between a number of people in relation to the object, and how the object is regarded within the prevailing political system. Most broadly and concisely, property in the legal sense refers to the rights of people in or over certain objects or things.

Non-legally recognized or documented property rights are known as informal property rights. These informal property rights are non-codified or documented but recognized among local residents to varying degrees.

Justifications and drawbacks of property rights.

In capitalist societies with market economies, much of property is owned privately by persons or associations and not the government. Five general justifications have been given on private property rights:

1. Private property is an efficient way to manage resources in a decentralized basis, allowing expertise and specialization to develop with regard to the property.

2. Private property is a powerful incentive for owners to put it to productive use because they stand to gain in the investment.

3. Private property allows exchanges and modifications.

4. Private property is an important source of individual autonomy, giving individuals independence and identity distinct from others.

5. Private property, being dispersed, allows individuals to exercise freedom, against others or against the government.

Arguments in favor of limiting private property rights have also been raised:

1. Private property can be used in a way that is harmful to others, such as a factory owner causing loud noises in nearby neighborhoods. In economics, this is known as a negative externality. Nuisance laws and government regulations (such as zoning) have been used to limit an owners' right to use the property in certain ways.

2. Property can lead to monopolies, giving the owner the power to unfairly extract advantages from others. Because of this, there are often laws on competition and antitrust.

3. Property can lead to the commodification of certain domains which people would prefer not to be commodified, such as social relations. There is debate in certain countries, for example, on whether organ sales or sex services should be legal.

4. Private property gives individuals power, which can exacerbate over time and lead to too much inequality within a society. The propensity for inequality is justification of wealth redistribution.