Modern state interventions in society often encounter popular resistance, especially in developing countries where informal rules dominate and formal institutions that conflict with them find it difficult to gain legitimacy. How can we achieve the transition to a legitimized rule of law in an unfavorable environment where informal rules do not support it? Based on a comparative case study of two villages in China, this paper argues that grassroots bureaucrats' obfuscatory work - work on blurring the conflict between formal and informal rules - can gradually change the legitimacy of formal rules and thus have a long-term impact on the political ecology. Specifically speaking, by describing the different obfuscatory efforts officials can take in the pre-, mid-, and post-policy implementation stages, this paper analyzes in detail how officials can enhance or diminish the legitimacy of formal rules in five dimensions: legibility, universality, obligation, favorability, and public-private distinction of the rules. The more officials work to make formal rules exhibit these five characteristics, the more the legitimacy of formal rules will increase and people more likely to build the habit of following formal rules. Meanwhile, this paper also challenges the dualistic "resistance-compliance" framework that pervades the scholarship on state intervention and social response by claiming that obfuscatory work constitutes the main part of everyday politics.