10.9

Chapter: Terrain

10.9

Translation:

Should the army forestall you in occupying a pass, do not go after him if the pass is fully garrisoned, but only if it is weakly garrisoned.

Commentary

If the other side gets to the pass first and has created a garrison, attacking this is wasteful and likely futile, like laying siege.

The best hope is that the enemy is careless and has insufficient guards, allowing you to charge in with a wholesale attack, or maybe creep in at night.