[1] He is most noted as cowriter with Darrell Dennis and Medina Hahn of Inheritance: a pick-the-path experience, a stage play which was shortlisted for the Governor General's Award for English-language drama at the 2022 Governor General's Awards.
[2] Born in Nelson, British Columbia, and raised in Edmonton, Alberta,[3] he studied theatre at the University of Alberta as a classmate of Hahn, with whom he has remained closely associated as partners in the DualMinds theatre company.
[5] In 2008, when Daniel MacIvor won the Siminovitch Prize in Theatre, he selected Arnold and Hahn as the winners of the Protégé honour.
[11] His play Inheritance: a pick-the-path experience is a stage play about indigenous land claims which features points at which the audience can vote on the direction the story would take, requiring the actors to be prepared for at least 50 different possible permutations of the performance.
[2] His other plays have included Tuesdays & Sundays,[13] Any Night,[14] and The Ridiculous Darkness.