When the battalion is acting alone, the intervals depend upon the purpose of the combat. In the fights around Mukden, some of the Japanese battalions, stationed at points where the decision was not sought, were each assigned a front of 800 m. In these cases the four companies of each battalion had to be deployed abreast of each other at large intervals. [Illustration] It is impossible to prescribe fixed forms of deployment for particular situations. In each case the formation of the battalion depends upon the situation, the purpose of the combat, and the nature of the ground, the battalion commander having the option of going into action in one, two, or three lines. Moreover, the formation depends upon whether-- 1. The battalion is acting alone or as part of a larger force; and whether one or both of its flanks are resting on impassable obstacles; 2. Whether it is fighting a decisive or a containing action; whether it is to attack or to stand on the defensive; 3. Whether it is to prepare the attack by its own fire or is to take advantage of the preparation effected by other troops; and, finally, 4. Whether or not it has to fight at night. =A battalion acting alone=, whose flanks are not resting on natural obstacles, will, as a rule, place entire companies successively into action so as to retain complete organizations for other purposes. It will seldom be proper for the battalion to form for attack in the regular manner. When this can be done the battalion should form in three lines in conformity with its task of initiating, carrying out, and deciding the fight. In this case the leading company is reinforced by the second company as soon as the situation has become sufficiently clear. More frequently, the battalion commander will send only a single company into action, retaining the others for the time being under cover. [Illustration] The =advance guard battalion= of a regiment will, as a rule, be compelled to develop considerable fire in a _rencontre_ (par. 357 German I. D. R.), in order to check the advance of the enemy, and for this purpose it will frequently place two companies into action at once. But since the battalion commander cannot count upon reinforcements and, moreover, as he does not know on which flank the combat is subsequently going to develop, he will provisionally retain the other two companies in rear of the center, or echelon them in rear of both flanks. (See “a” and “b” above figure). [Illustration]