Responsible gambling
Offshore casino sites set their minimum age at 18. Licensed venues inside New Zealand set theirs at 20. Either way, gambling is an adult activity that costs money, and the money it costs should be money already earmarked for entertainment.
What goes wrong usually looks unremarkable at first. Sessions that run longer than planned. A deposit made to win back the last one. Play that moves to hours when nobody else is awake. Balances checked before anything else in the morning. None of these is proof of a problem on its own, and all of them are worth noticing.
Deposit caps, loss caps, session timers and self-exclusion are built into the account settings of every brand ranked here, and a reduction takes effect straight away while an increase waits out a cooling-off period. Two services in New Zealand take that conversation free of charge and in confidence: Gambling Helpline NZ, reachable any hour on 0800 654 655, and the Problem Gambling Foundation, whose counsellors also see whanau and friends rather than the player alone.