House Bill 5999 creates four rules to use in the substance of the dispute. (1) The arbitrators must decide the dispute following any rules of law that are chosen by the parties as applicable to the substance of the dispute. Requires that any designation of the law or legal system of a given jurisdiction to be construed, as directly referring to the substantive law of that jurisdiction and not to its conflict of law rules. (2) If the parties do not make such a designation, the arbitrators must apply the law as determined by the conflict of laws rules that they consider applicable. (3) The arbitrators must decide according to the strict rules of law unless the parties have expressly authorized some other standard. (4) In all cases, the arbitrators must decide according to the terms of the contract and take into account the usages of the trade applicable to the transaction. This case will impact all Illnois law.