There are 28 reported decisions arising out of cases that Royden was engaged in during the period from 1986 to 2002, and a further 19 decisions in that period have been noted up in various annotation services.
Royden has appeared as amicus curiae in the Maori Land Court, and in the High Court. In addition he has been involved in a number of substantial arbitrations, both as counsel and as Arbitrator. Before taking on the role of Chairperson of the Human Rights Review Tribunal on a full time basis in 2005, he conducted a number of successful mediations.
During 1999/2000 Royden acted as counsel assisting the Gisborne Cervical Screening Inquiry. Since 2002 he has been Chairperson of the Human Rights Review Tribunal (all decisions of the Tribunal since 2002 are at http://www.nzlii.org/nz/cases/NZHRRT/). He was independent director of Mangakahia Forests Limited from 2004 to 2009.
Royden has been a Trustee of the New Zealand International Yachting Trust since its establishment in 1986. He has participated actively in on-shore and off-shore yachting events, including the Pan Am Clipper Cup (Hawaii, 1984), Sydney/ Hobart events (1990 and 1992), Flying Fifteen National Regattas (1995, 1996 and 1997) and the World Championship event in Hong Kong (1995).