This book unveils gaps, inconsistencies, and barriers to accountability emerging from the intersections between IHL and ICL in the definition and treatment of indiscriminate and disproportionate attacks as jus in bello violations. The book identifies and explains the unresolved legal problems surrounding the prevention and control of indiscriminate and disproportionate attacks as international war crimes, and critically unpacks the macroscopic implications of these problems for international adjudications.It goes on to address the challenges posed by these attacks as key causes of civilian victimization in war. The author demonstrates that the Rome Statute of the ICC, legibus sic stantibus, does not allow to prosecute and punish the most recurring forms of indiscriminate and disproportionate attacks, crucially impairing the ability of this institution to pursue the objectives declared by its founding treaty.It concludes by offering two amendment proposals for the Rome Statute to bridge the gaps and overcome the antinomies identified.