Methods
A sample of 1,075 Australian adults aged 18–49 years who planned to watch an National Rugby League (NRL) State of Origin series game, featuring prominent alcohol sponsorship, was recruited through an online panel and randomly assigned to one of three conditions: control (neutral advertisement); counter-advertisement exposing alcohol harms; counter-advertisement exposing alcohol sponsorship and harms. Participants completed a pre-test questionnaire and viewed their assigned counter-advertisement multiple times in the 5–7 days before the NRL game. Within four days of watching the game, participants completed post-test measures.