The possession of land, without legal title, for a period of time sufficient to become recognized as legal owner.
The more common word for this is "squatters."
Each state has its own period of time (limitation period) after which a squatter can acquire legal title or some states (like the Canadian Privince of British Columbia) prohibit title by mere prescription or possession.
The law was well settled in Wood v Leblanc in which justice Davies adopted these words:
"To enable the (trespasser) to recover he must show an actual possession, an occupation exclusive, continuous, open or visible, and notorious for twenty years. It must not be equivocal, occasional or for a special or temporary purpose.... (T)he trespasser to gain title must as it were 'keep his flag flying over the land he claims.'
"Now, in my judgment, the possession necessary under a colourable title to oust the title of the true owner must be just as open, actual, exclusive, continuous and notorious...."
This was supplemented by the Supreme Court of Prince Edward Island in National Trust:
"The defendant must establish that it has had open, notorious, continuous and exclusive possession for 20 years.
"What does each of these terms mean?
"The terms open and visible are straightforward meaning that the person claiming must be seen on the land. The acts and possession of the person setting up the adverse claim must be of such a nature that the true owner might know of them, although it is not necessary that the true owner is aware of the possession.
"The terms constant or continuously mean that the adverse possession must be for the terms of the limitation period, in this instance, 20 years (in PEI). The constant or continuous possession cannot be sporadic or occasional. There can be no interruption and if there is, then the property reverts to the true owner."
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