The Leges inter Brettos et Scottos or Laws of the Brets and Scots was a legal codification under David I of Scotland (reigned 1124 – 1153). Only a small fragment of the original document survives, describing the penalties for several offences against people.
Historically, the term "Brets" refers to Brythonic peoples, while "Scots" refers to Gaelic-speaking peoples. Skene however, asserted that here "Scots" refers to all of the peoples living north of the firths of Clyde and Forth.
Aside from the document's intrinsic importance to Scottish history, it is significant in its similarity to corresponding areas both of Irish Brehon law and of Welsh law, which are better-preserved than the laws of medieval southern Scotland, allowing reasonable conjectures to be made regarding the laws and customs of the region, as few historical records exist.
The Laws or their precursor were relevant in the early twelfth century, as the Laws of the Four Burghs (Latin: Leges Quatuor Burgorum) explicitly banned parts of it relating to the cro (or weregild).
The Laws are known to have been relevant until 1305, as Edward I of England specifically abolished them in that year, following his invasion of Scotland. There is no further mention of them, and when Scotland successfully reasserted its independence, the feudal Scots law then became applicable.
The surviving clauses show the society's origins as a tribal culture, where a perpetrator's family is responsible for the perpetrator's transgressions, and the family of a victim is compensated for the loss of a family member. As with other Celtic societies, the rights and obligations of women are explicitly guaranteed (though at a lesser standing than that of men). Marriages are treated as relationships between different families, and payments accrue to the family of the victim's spouse under some circumstances, but accrue to the victim's family under other circumstances.