International law of armed conflict contains basic principles and rules governing the choice of weapons and prohibits or restricts the use of certain weapons. The main criteria assessing whether a particular weapons is clasified as prohibited are two basic principles, the priciple of the distincion between civilians and combatants and the prohibition of inflicting unnecessary suffering to combatants. When there is no specific applicable rule of international law of armed conflict, the parties to the armed conflict should always keep in mind that their actions must be in accordance with the principles of humanity and dictates of the public conscience, as a minimum established by the Martens clause. Considering the variety and number of weapons, the paper focuses on two large groups of weapons, conventional and weapos of mass destruction. In relation to these groups, the paper shows the development of the rules of international law of armed conflict, from the first formal prohibition of a certain type of weapon in 1868. until the attempt to compehensively ban nuclear weapons, as the most dangerous type. By adopting the rules applicable in armed conflict and in connection with it, the international community makes efforts to be one step closer to the realization of the ultimate goal, the humanization of warfare.