Having “a sense of humor” when negotiations get tough has very little to do with being funny. Enacting rather than claiming, performing rather than arguing, mediators’ humor reveals multiple meanings and uncertainties, multiple perspectives and their limits, and parties’ needs while generating opportunities to learn. Humor can go wrong, and mediators stress a sine qua non: it must be respectful, never used at the expense of a negotiating party. At critical moments in negotiations, humor can be an important tool, if improvised with regard to tone, timing, affect, and respect. Mediators use humor to deconstruct and reconstruct parties’ presumptions of mediators’ authority; to recognize vulnerability, create moments of intimacy, and suggest possible community; to acknowledge painful histories and enable difficult conversations; to provide safety, release, and new collaborative openings. Mediators’ use of humor can signal possibility and hope and, not least of all, level power to encourage autonomy and build capacity — thus creating deliberative space and encouraging deliberative practice as well.