Lex fori

Lex fori (Latin: the law of the forum) is a choice of law rule. If applicable, it provides that the law of the jurisdiction or venue in which a legal action is brought applies.
When a court decides that it should, by reason of the principles of conflict of law, resolve a given legal dispute by reference to the laws of another jurisdiction, the "lex causae", the "lex fori" still govern procedural matters.