Legal systems across the world contain the obligation to prevent ‘absurd interpretations’ of law. In international law, an instruction to avoid ‘manifestly absurd’ interpretations can be found in Article 32 of the Vienna Convention on the Law of Treaties. This gives rise to at least two questions that I will take up in this article. First, what is meant by the ‘absurd’ that is to be avoided in legal interpretation. The short answer to this question is: no one knows exactly. The absurd, by its very nature, resists definition in pre-given categories, as I will argue on the basis of four core thinkers on the absurd: Søren Kierkegaard, Jean-Paul Sartre, Albert Camus, and Thomas Nagel. The second question is more technical and easier to answer: how should lawyers try to avoid absurd interpretations? Here, I turn to absurdist writing and the theatre of the absurd for assistance. Absurdist writing and theatre have developed a number of techniques to make the absurd appear, to let the audience experience that something is fundamentally out of tune. Lawyers use similar techniques, but in reverse and with an opposite purpose: they add exposition, narrative, reasonable language, and stable, rational legal personae. In this way, they boost the rationality and reasonableness of the legal order. However, to come full circle, it is exactly the pretension of rationality and reasonableness that makes the law vulnerable to manifestations of the absurd. The rationality of law is the springboard for the very same absurdity it tries to suppress.