Organizational culture is the invisible framework through which power, influence, and legitimacy operate. It shapes how people interpret rules, relate to authority, handle conflict, and decide what behaviors are acceptable or risky—often overriding formal structures and strategies. This chapter shows that culture is socially constructed and reinforced through everyday practices: values, language, rituals, symbols, and informal norms. As organizations grow, culture fragments into subcultures by function, hierarchy, profession, geography, and other elements, creating both coordination and political friction. Across the cases, a consistent pattern emerges: success is driven less by technical competence than by cultural alignment and networking. Those who understand and adapt to cultural codes gain access and influence; those who violate them—often unintentionally—face resistance or exclusion. Culture is therefore inherently political. It defines who belongs, who is trusted, and whose voice counts. Leaders shape culture continuously through what they reward, tolerate, or ignore. Attempts to change organizations without addressing cultural dynamics are likely to fail. For managers and executives, cultural literacy is a prerequisite for effective leadership and political navigation. Culture is far from being a “soft” variable—it is a decisive source of power.