Staff in gaming venues are increasingly expected to identify people with possible gambling problems based on observable behaviour. We report on interviews with 48 venue staff in Queensland, Australia with the goal of assessing whether they feel they can detect patrons with possible gambling problems, and what indicators they use to assess this and to decide whether to intervene. Results showed wide variation in the indicators used by these staff members with only one indicator, aggressive behaviour, reported by the majority. Most contemplated intervening only if patron behaviour is seen as a threat to themselves or others. Venue staff would benefit from clearer direction on indicators of problem gambling behaviour and when to intervene.