When was murder completely leagel?

Murder has never been completely legal in any society. Throughout history, various civilizations have had different laws and norms regarding killing, but generally, murder has been considered a crime. Some societies have practiced forms of legalized killing, such as during wartime or in the context of capital punishment, but these are exceptions rather than a blanket legality of murder itself. Overall, the act of murder is universally condemned and punished across cultures and legal systems.