Beauvoir wrote Les Bouches inutiles in the winter of 1943–44, in Occupied Paris, alongside her novel The Blood of Others. Gallimard published the play text in April 1945. It opened at the Théâtre des Carrefours in the 5th arrondissement of Paris on 29 October 1945, directed by Michel Vitold, with Olga Kosakiewicz — Beauvoir's former student and the model for Xavière in She Came to Stay — in a small role. Fifty performances into the run the play closed. Beauvoir wrote in The Prime of Life (1960) that she thought the play deserved to close: she had loaded it with dialogue that read but did not sound. Claude Francis and Fernande Gontier's English translation, Who Shall Die?, appeared from River Press in New York in 1983 — thirty-eight years after the Paris production.
The play is set in the town of Vaucelles in fourteenth-century Flanders. The Duke of Burgundy is besieging the town. Food is running out. The town's ruling council — men — decides, at the play's opening, to expel from the walls the women, children, elderly, and sick who cannot fight, so the food supply reaches the defenders. The proposed victims — the 'useless mouths' of the French title — organise. The rest of the play works out the argument between the council and the condemned, and the specific test-case of one family: Louis d'Avesnes, the council leader; his wife Catherine, whom he has just condemned; and their daughter Clarice.
The play is Beauvoir's philosophical argument in dramatic form. It refuses two positions. The first, that political action is justified by any future good it makes possible (the council's position), is refused: the council does not have the right to declare part of the community disposable in the name of preserving the rest. The second, that no political action is legitimate at all if it costs a life (the pacifist position that surfaces briefly), is refused too: the town cannot simply surrender to the Duke and be spared thinking about who bears the cost. The play's answer, closer to what The Ethics of Ambiguity would say two years later, is that the condemned must be brought into the decision and given the right to accept or refuse it themselves. The play's staging of that answer — with a woman who has been marked for death being reinstated as a full participant in the town's choice — is the philosophical case in ten scenes.