The core of Lin Biao's tactics is based on six strategic principles summarized during the Liberation War period on the Northeast battlefield. These principles are adapted to the enemy situation and environment in Northeast China and have become important operational guidelines for the Fourth Field Army. The specific content is as follows:

1. One Point, Two Sides: Concentrate forces on the main attack point to avoid dividing forces; at the same time, encircle the enemy from at least two sides (three or four sides when forces are sufficient) to prevent their breakout, balancing breakthrough and complete annihilation objectives.

2. Four Fast, One Slow: "Four Fast" refers to advancing, preparing for combat, rapidly expanding after breakthroughs, and pursuing and defeating the enemy quickly; "One Slow" specifically means the main attack should be launched slowly, after thorough preparation, to avoid hasty combat.

3. Three Fierce Tactics: namely fierce attack, fierce charge, and fierce pursuit. Focus firepower on the main attack point to strike the enemy fiercely, charge bravely when the enemy is in chaos, and continuously pursue the disorganized enemy without giving them a chance to breathe.

4. Four Groups, One Team: use company units as operational units, divided into firepower group, assault group, demolition group, and support group. Each group works collaboratively and covers each other to improve assault efficiency, playing a significant role in battles such as Jinzhou and Tianjin.

5. Three-Three System: each squad is divided into three groups; during attack, formations are dispersed to avoid dense casualties and facilitate command by squad leaders. However, this tactic is not suitable for pursuit battles.

6. Three Situations, Three Strategies: different strategies are adopted depending on whether the enemy is holding firm, hesitating and not retreating, or retreating in disorder—namely, attack after thorough preparation, encircle without attacking and wait for an opportunity, and decisive fierce pursuit.

Additionally, he proposed the "hard fight" tactic on the Northeast battlefield, which involves engaging the enemy with several divisions when conditions are not ideal but it is necessary to strike their morale. This tactic relies on about 60-70% confidence in victory, fighting decisively even if complete annihilation is not possible, aiming to inflict heavy damage on the enemy and turn the battlefield situation.