Defilade refers to a
tactical position assumed by a military force where they are located behind a
ridge, a hill summit, or some other
terrain feature that is a high point relative to the
enemy. In this position, the geographic feature both hides them from view, and provides physical protection. Defilade offers an excellent
hasty position to defend from, because the natural terrain features form a barrier that often needs no additional construction. Then enemy when located on the same slope as the defiladed force but below the summit, exposed to fire, is considered to be
enfiliaded.
Defilade is a particularly advantageous position for armored vehicles such as tanks, in that they can back behind the ridge far enough to be completely invisible, yet occupy a firing position within seconds. More than one firing position may be created. In a defiladed firing position, only the vehicles turret need be exposed, which offers significant advantage to the defender. The amount of exposure is partly dictated by the amount of main gun depression designed into the vehicle.
While advantageous, the use of defiladed positions is not always advisable. The enemy also knows the benefits of such positions, and an artillery-rich force may choose to bombard likely positions ahead of schedule. Good deflilade spots are likely artillery targets. For this reason, it may prove better to defend on the enfilade when facing an enemy with significant artillery capabilities.