New evidence suggests smoking addiction occurs primarily among young adults, whose smoking prevalence, particularly among Maori and Pacific, remains disproportionately high. While on-pack warnings promote quit attempts among some smokers, cessation rates could be enhanced if these warnings better recognised and influenced the very different sub-groups within the wider smoker population. This project will extend our pilot studies, apply international findings to New Zealand, and test how young adult non-smokers, smokers, and recent quitters interpret and respond to social, denormalisation, SHS, and health warning themes. The proposed mixed-methods study will provide an evidence base that results in more effective on-pack warnings and campaigns linked to these. The results will, for the first time, inform use of more targeted and salient messages that better address inequalities. New measures to deter initiation, encourage cessation, and maintain new smokefree behaviours among this group will be pivotal in realising the Tupeka Kore 2025 goal.