Standard contracts drafted by trade associations are considered a traditional part of soft law, or rather a source of lex mercatoria. These instruments, emerging largely in response to the changing needs of international trade, assume a leading role in a number of sectors. One of the sectors traditionally relying on standard contracts is commodity trade. This chapter thus seeks to offer some insights into the role of standard contracts in contemporary contracting and decision-making practice, specifically against the socio-historical background of the formation and development of specialized commodity associations. This link should serve as a prerequisite for explaining why these standard contracts include a number of typical clauses that may seem archaic in the context of contemporary international trade. The same is true for some of the features of the specialized arbitration system created and administered by trade associations to resolve disputes arising among their (not only) members. The chapter concludes by stating that trade associations occupy an irreplaceable position in international trade, with all aspects of their activities in the field of institutionalized standardization constituting a primary factor of the widespread application of standard contracts, thus reinforcing their position as part of lex mercatoria.