To resolve conflicts and disagreements in planning, a compromise is often necessary. Where immediate consensus is unlikely and where antagonistic conflicts can lead to worse outcomes, a compromise is especially valued. Yet a compromise is also likely the least desired resolution, except for failure to reach a resolution. In this way, a compromise educes a mixed morality: A compromise has to presume some cooperative goodwill, yet forging a compromise often means violating important principles or abandoning some desired goods. If planners compromise, then this compromise ought to be an ethical one. But what is an ethical compromise in planning? In this article, we examine three cases of planning conflict: namely, the case of the Storm Surge Barriers in the Eastern Scheldt, the Netherlands; the case of the Cross Island Line in Singapore; and, finally, the case of the Calamity Polders, the Netherlands. Through these case studies, we draw out and illustrate three different ideal types of compromises important to planning and further describe the practical and ethical implications of a compromise.