In the United States, “squatter’s rights” isn’t a list of specific rights, but refers to a specific form of adverse possession, a legal principle that we inherited from England and has been around, in one form or another, for ages.

Adverse possession allows for real estate to change ownership without payment if someone occupies another person’s property while meeting certain requirements for a set amount of time without the owner getting rid of them. For example, if I build a fence way over my neighbor’s property line and use and maintain the land I’ve fenced off, and my neighbor does nothing about it for a while (exactly how long depends on where we live), I may be able to claim that chunk of his property as my own if he does ever make a fuss.

The idea behind adverse possession, the California Court of Appeals for the Third District wrote in a 1979 decision, “is basically that land use has historically been favored over disuse, and that therefore he who uses the land is preferred in the law to he who does not, even thought the latter is the rightful owner. Hence our laws of property have sanctioned certain types of otherwise unlawful taking of land belonging to someone else.” The purpose, the Court continues, isn’t “to reward the taker or punish the person dispossessed, but to reduce litigation and preserve the peace by protecting a possession that has been maintained for a statutorily deemed sufficient period of time.”

While the principle is usually used by the courts to resolve property disputes like my hypothetical fence, squatters can also use adverse possession to gain ownership of the property they’re squatting in if they play their cards right.