The International Criminal Court (ICC) Prosecutor's preliminary examination of alleged international crimes committed in the "war on drugs" in the Philippines highlights frictions between the ICC's universalist aspirations and the diversity of domestic approaches toward prosecuting international crimes. These remain prominent following the withdrawal of the Philippines from the Rome Statute of the ICC. This article argues that whether the ICC still commences a full investigation, or actors within the Philippines pursue investigations or prosecutions concerning the "war on drugs", legislation within the Philippines will play an important role. First, the legal framework for prosecuting international crimes in the Philippines affects ICC action by virtue of the complementarity principle. Secondly, in the absence or continued delay of any ICC investigation, any prosecutions of the alleged international crimes are more likely to occur within the Philippines under its laws, in which case those laws' connections to international criminal law are of interest. Thirdly, the content of the laws that allow domestic courts to prosecute international crimes reveals information about how international criminal law is influenced and implemented in different contexts, including the Philippines. This article argues that examining domestic international crimes laws in the Philippines, and their enforcement, demonstrates how the ICC's approach to international criminal law can affect, and be adapted by, politicians, civil society and other actors, institutions and procedures. Apart from establishing legislative ability, this information might contribute to assessments of whether a state is unwilling genuinely to prosecute or investigate cases, as well as broader information about the implementation of international criminal law.