If the invader chooses the hard pass he will lose one battalion of his army simply in getting over the mountains, simply in going through the hard pass.

如果侵略者选择崎岖的路,仅在穿越阿尔卑斯山的途中,他就要损失一个营的兵力,这就是选崎岖之路的代价

耶鲁公开课 - 博弈论课程节选