A booby trap may be defined as any concealed or camouflaged device designed to cause bodily injury when triggered by any action of a person making contact with the device. This term includes guns, ammunition, or explosive devices attached to trip wires or other triggering mechanisms, sharpened stakes, nails, spikes, electrical devices, lines or wires with hooks attached, and devices for the production of toxic fumes or gases.
If a person sets up such a trap to protect his/her property, he/she will be liable for any injury or death even to an unwanted intruder such as a burglar. It is illegal to set a booby trap on one's own property to prevent intruders.
The Geneva Convention, which applies to law governing wars, deals with booby traps as follows:
Without prejudice to the rules of international law applicable in armed conflict relating to treachery and perfidy, it is prohibited in all circumstances to use:
a. any booby-trap in the form of an apparently harmless portable object which is specifically designed and constructed to contain explosive material and to detonate when it is disturbed or approached, or
b. booby-traps which are in any way attached to or associated with:
1. internationally recognized protective emblems, signs or signals;
2. sick, wounded or dead persons;
3. burial or cremation sites or graves;
4. medical facilities, medical equipment, medical supplies or medical transportation;
5. children's toys or other portable objects or products specially designed for the feeding, health, hygiene, clothing or education of children;
6. food or drink;
7. kitchen utensils or appliances except in military establishments, military locations or military supply depots;
8. objects clearly of a religious nature;
9. historic monuments, works of art or places or worship which constitute the cultural or spiritual heritage of peoples;
10. animals or their carcasses.
It is prohibited in all circumstances to use any booby-trap which is designed to cause superfluous injury or necessary suffering."