On a somewhat related note, that Sun Tzu quote reminds me of something he did. Sun Tzu had a rivalry with this other general who he often got into skirmishes with and always defeated him or outmaneuvered him with some kind of trickery. So one time this rival general actually had Sun Tzu on the ropes and had chased him into a bit of a corner. Sun Tzu was in a smallish fort with the enemy general closing in and he definitely did not have enough soldiers to hold the fort for long.
So instead of trying to intimidate his rival with a show of force or making his army seem bigger than it was or whatever else he might have tried instead when his rival arrived at the fort he found the front gate fully open and nobody in sight except Sun Tzu himself sitting on the battlement playing an instrument somewhat akin to a lyre I think.
His rival was so wary of trickery that he assumed it must be a trap, or a distraction while a larger army moves in to reinforce him, so he left and Sun Tzu and his army survived.
Oh interesting! I must have mixed my facts up or something, my bad. You’re right that it’s attributed to Zhuge Liang, but it seems like Wikipedia thinks it was a fictional story when attributed to Zhuge Liang, but it looks like he wasn’t the first to use this strategy and he wasn’t the last. Regardless, I was wrong about Sun Tzu having done it and I learned more about history, so thanks!
Here’s the Wikipedia article I was referring to: https://en.wikipedia.org/wiki/Empty_Fort_Strategy#Zhuge_Liang