The lex loci arbitri is the Latin term for "law of the place where arbitration is to take place" in the conflict of laws. Conflict is the branch of public law regulating all lawsuits involving a "foreign" law element where a difference in result will occur depending on which laws are applied.
Explanation
When a case comes before a court and all the main features of the case are local, the court will apply the lex fori, the prevailing municipal law, to decide the case. But if there are "foreign" elements to the case, the forum court may be obliged under the conflict of laws system to consider:
whether the forum court has jurisdiction to hear the case ;
it must then characterise the issues, i.e. allocate the factual basis of the case to its relevant legal classes; and
then apply the choice of law rules to decide which law is to be applied to each class.
The lex loci arbitri is an element in the choice of law rules applied to cases testing the validity of a contract. As an aspect of the public policy of freedom of contract, the parties to an agreement are free to include a forum selection clauseand/or a choice of law clause and, unless there is a lack of bona fides, these clauses will be considered valid. If there is no express selection of a proper law, the courts will usually take the nomination of a forum as a "connecting factor", i.e. a fact that links a case to a specificgeographical location. For these purposes, one of the "forums" that may be selected is arbitration. Hence, the fact that the parties have chosen a state as the place of arbitration is an indication that parties may have intended the local law to apply. This indication will be weighed alongside other connecting factors. The state that has the largest number of connecting factors will be the lex causae applied to resolve the dispute between the parties. If there is a tie, the connecting factors which relate to performance will be given a greater weighting.