In this research paper, the idea of Regulatory Stewardship is approached as a guiding philosophy for regulatory reform and its development and current state is contrasted with other such guiding philosophies. Considering the complexities of regulation, regulators should look at the performance of their regulatory systems in full rather than at the performance of parts of it when pursuing regulatory reforms. Regulatory reforms have long been approached, unintentionally, as zero-sum games in which improvements of some parts of regulatory systems would ask for sacrifices of other parts—typically, increased cost-effectiveness has been traded off against reduced accountability, transparency, equity, or certainty. When looking at the performance of regulatory systems in full, regulators are forced to think about such trade-offs early on. Arguably, the Regulatory Stewardship experience in New Zealand illustrates that changing this mindset is possible despite many challenges.