This qualitative study explores school principals' perceptions and enactments of shared sense-making processes during a generally-outlined pedagogical reform, i.e. "a broad-policy reform allowing educators to exercise their discretion in meeting its pedagogical goals," aiming to inquire what makes such processes critical to schools' collective efficacy within reform implementation. Interviews with 25 high school principals implementing this reform in state and religious-state schools produced data, whose analysis yielded two major themes and sub-themes: (1) Communicating a shared vision: (a) a shared pedagogical vision; (b) a shared values-based vision; (c) a shared vision of pedagogical bluff; and (2) Strengthening school collective efficacy: (a) facilitating a collaborative instructional culture; (b) adjusting school reality toward instructional focus. A shared sense-making process offers a beneficial framework for principals and teachers collectively navigating complexity and uncertainty, while implementing ambiguous pedagogical policy demands within their unique contexts.