Genocide:
-10 for killing the last remaining unit of any power, including POWs.
Conspiracy with the enemy (e.g. Germany and USSR standing by their nonaggression pact despite a phony declaration of war):
Germany gets -3 for every turn after round 4 that Germany has not attacked any Soviet controlled territory or naval unit and has not placed any warships in z125.
USSR gets -3 for every turn after round 4 that USSR has not attacked any German controlled territory or naval unit and has not placed any warships in any German convoy raid zones.
Plunder:
Anytime you capture an enemy’s capitol and seize their national treasure (gold, money, works of art, secret files, execution of intellectuals, etc.) you incur -5 war crimes points.