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:
2. It is prohibited in all circumstances to use any booby-trap which is designed to cause superfluous injury or necessary suffering."