§ 172.104.Rules of Evidence

One sentence that replaces an entire evidence code.

Four determinations are handed to the tribunal: admissibility, relevance, materiality, and weight.

Weight is the significant inclusion. A tribunal that admits everything and weighs it is doing something different from a court applying exclusionary rules.

That is the international practice. Documents and testimony are generally received and given the weight they deserve, rather than excluded by categorical rules.

The power comes from Section 172.103(b), so it applies where the parties have not agreed on the procedure.

The parties can supply their own evidence rules, by agreement or by adopting institutional or soft-law rules that many international arbitrations use.

Equal treatment still governs. Section 172.101 requires a full opportunity to present a case, so evidentiary rulings cannot leave one side unable to make its argument.

Chapter 171 takes the opposite approach, borrowing district court practice for oaths, depositions, subpoenas and witness fees.

The section says nothing about compelling evidence, which is a separate question answered by Section 172.105 for subpoenas and Section 172.172 for court assistance.

The four determinations are related but distinct. Admissibility asks whether the tribunal will receive the material at all; relevance and materiality ask what it bears on; weight asks what it proves.

Weight is where most of the work happens. A tribunal that receives a document of doubtful provenance can take it for what it is worth rather than exclude it.

Reasoned awards make those judgments visible. Section 172.141(b) requires the award to state the reasons on which it is based, so the treatment of the evidence appears on the face of it.