A military booby trap may be used to give away the location of an enemy by triggering a signalling device, or it may be designed to kill or injure a person who activates the trap. Most, but not all, military booby traps involve explosives.
There is no clear division between a booby trap and conventional, mass-produced land mines which are usually hidden under soil, but may be triggered by a tripwire or directional mine designed specifically to work with a tripwire. Other, similar devices include spring-guns and related mechanisms such as the SM-70 directional antipersonnel mine.
What distinguishes a booby trap is that it is contrived to work in an unexpected manner that takes advantage of the victim’s ignorance of the mode of operation. It naturally follows that booby trap designs must be many and varied, and for this reason the traps are often at least partially improvised from some item of ordnance, such as an artillery shell, grenade, or quantity of high explosives. However, some mines have features specifically designed for incorporation into booby traps and armies have been equipped with a variety of mass-produced triggering mechanisms intended to be incorporated into booby traps in a wide variety of ways.