Mines are among the best artificial obstacles---they are portable, installed relatively easily, and constitute a hazard to the enemy; however large scale employment of mines requires considerable time, manpower, and logistical effort. Mines delay and canalize enemy movement, lower the enemy's will to fight, and cause fear of sudden and unexpected casualties. Mines, in contrast to passive obstacles such as road craters and barbed wire, are termed active obstacles because of their destructive potential. If placed in a location where movement is confined such as at a ford or on a bridge approach, a few mines can create an obstacle; however, mines are more frequently employed to create obstacles by distributing them in quantity over a relatively large area. Although mines may be used individually for the purpose of causing casualties, this manual is primarily concerned with the employment of mines as obstacles.