Psychological safety is a fundamental human need that profoundly shapes how individuals engage, collaborate, and grow within organizations. This publication explores what psychological safety truly means, how its absence manifests in workplace dynamics, and why its presence is essential for sustainable performance and inclusion. Grounded in the four stages of psychological safety, we provide concrete tools and strategies leaders and teams can use to assess and strengthen it in daily practice. Drawing on over a decade of experience, WeAreOpen offers insights into how psychological safety drives both individual well-being and long-term organizational success.