A weapon or armament is any device used with intent to inflict damage or harm to living beings, structures, or systems. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, self-defense, and warfare. In a broader context, weapons may be construed to include anything used to gain a strategic, material or mental advantage over an adversary. While some weapons are improvised and others are repurposed from common tools or devices, most are designed to inflict damage to beings and structures.