to substitute one thing for another, often sacrificing a minor part to save the whole

在这场博弈中，他采取李代桃僵之计，牺牲了局部利益以保全大局。

to be a scapegoat or carry the blame for someone else

真正的幕后黑手已经逃脱，他却成了李代桃僵的替罪羊。