Since the advent of sophisticated projectile weapons and siege artillery, it has become necessary for individual combatants to seek shelter, most commonly within earthworks or fortified structures. In the open, where missiles and bolts of energy fill the air, lingering for any length of time can be hazardous to one's health, and the odds of misfortune increase the longer one remains exposed. In addition to providing cover, fortified positions also conceal the strength of the force which guards them.

A foxhole is a general term used to describe a number of defensive structures designed to protect infantry units. Depending on the surrounding terrain, they may be either dug into the ground like a trench, dug into a hillside, or be built above ground. While different shapes and designs are used to accommodate any number of species or specialized equipment, the most sophisticated foxholes use hardened materials such as wood, metal, or duracrete to reinforce the natural earth barrier.