This chapter assesses the value of social complexity theory for contributing to understanding oppositional dynamics to gender+ equality. Therefore, it first presents this theory, drawing mostly on the works of Sylvia Walby in which this theory has been elaborated. The chapter identifies several core concepts of social complexity theory that are of crucial value: domain, regime, project, tipping point, feedback loop, and path dependency. It then proceeds to clarify these concepts for this book and presents some amendments to these concepts. The chapter proposes two additional domains (episteme and cathexis) to Walby’s four (polity economy, violence, and civil society) and highlights the importance of integrating attention of issues of gender identity and gender expression in the gender regime. After articulating and amending these theoretical concepts, the chapter focusses son the European context, describing worrying changes in Europe as changes in domains and regimes.