Nec vi, nec clam, nec precario
'not by force, nor stealth, nor the licence of the owner'.

UK:
"Adverse possession is the term used to describe a claim to ownership of land arising not from a deed in favour of the claimant but from actual occupation of the land. Obviously it would not be fair or practical to allow a person to claim ownership merely by entering onto the land and so strict rules have developed in an attempt to balance the interests of land owners with the interests of the general public."
https://www.land-registry-documents.co.uk/news-blog/claiming...

USA:
Adverse possession is a doctrine under which a person in possession of land owned by someone else may acquire valid title to it, so long as certain common law requirements are met, and the adverse possessor is in possession for a sufficient period of time, as defined by a statute of limitations.

Common Law Requirements
The common law requirements have evolved over time and they vary between jurisdictions. Typically, for an adverse possessor to obtain title, his possession of the property must be:

Continuous--A single adverse possessor must maintain continuous possession of the property. However, the continuity may be maintained between successive adverse possessors if there is privity between them.
Hostile--In this context, "hostile" does not mean "unfriendly." Rather, it means that the possession infringes on the rights of the true owner. If the true owner consents or gives license to the adverse possessor's use of the property, possession is not hostile and it is not really adverse possession. Renters cannot be adverse possessors of the rented property, regardless of how long they possess it.
Open and Notorious--Possession must be obvious to anyone who bothers to look, so as to put the true owner on notice that a trespasser is in possession. One will not succeed with an adverse possession claim if it is secret.
Actual--The adverse possessor is actually in possession of someone else's property. The true owner has a cause of action for trespass, which must be pursued within the statute of limitations.
Exclusive--The adverse possessor does not share control of the property with any one else (unless in privity with himself). He excludes others from possession, as if he was actual owner.

https://www.law.cornell.edu/wex/adverse_possession