It’s a good thing that “Lemkin’s House” has its heart in the right place. Because nothing else in Catherine Filloux’s hot mess of good intentions, tonal wackiness, and misleading dead ends even comes close to the mark. There are otherwise staunch actors, forced to muscle meaning out of haphazard dialogue; there are the horrors of the 20th century, trotted out as scenery. And in the center of it all is a conceit so wet, so abysmally misguided, that it squelches any intensity the actors (or the tragedies) have managed to drum up for themselves.

Raphael Lemkin (John Daggett) has been dead for a while. After a fast expiration by heart attack (“Ouch. My arm! Can I get a glass of water?” cues the heavenly choir), he continues to hang about our earthly realm to see his law against genocide ratified by America. Even before his family’s death in the Holocaust, the real Lemkin was obsessed with extinguished peoples, and his every effort thereafter was focused on preventing it from happening again. His legacy isn’t only the codified international condemnation of ethnic cleansing, but even the word we use to do it — in the late ’40s, he actually coined the term “genocide.”

With “genocide,” Lemkin believed he was giving mankind a way to discuss and subsequently forestall mass murder. But as we (all too briefly) see, bureaucrats now use it as an excuse for inaction. When a U.N. official (Christopher McHale) won’t even utter “the g-word” out loud, it’s clear that the responsibility for any level of slaughter can be dodged, as long as no one dares call it by name. No one is more aware of his failure than poor, moldering Lemkin. Still dressed in the suit in which he died, he celebrates the ratification of his law with a bit of champagne, and settles down for a nice retirement. Of course, that’s before his “house” (a ham-fisted metaphor for his law) springs a leak, and through it pours refugees from Rwanda and Croatia, a rising tide of the targeted innocent.

Director Jean Randich and Mr. Daggett have settled on a portrait that is less a giant of human rights and more a Catskills comedian. It could be a fascinating juxtaposition, between the immense dignity of his cause and the man’s own high-elbowed, duck-footed capering. Unfortunately, the “Would you believe it? I’m haunted by the living!” shtick gets very old, very fast.And with Ms. Filloux’s total disregard for any of the strengths of the stage (characters do not change, tension is not established), this violation of conventionality just gets lost in the chaos.

Luckily, the supporting cast, especially Laura Flanagan, manages to make something out of nothing. Ms. Flanagan’s trembling Muslim waiting to die at the hands of the Serbs hasn’t been given the lines to convey her untenable, desperate position, so Ms. Flanagan does it practically by telepathy. She handles the fake baby (oh yes) and the kiss with the already dead human rights activist with gracious aplomb. Having won our sympathy, she then ratchets it up into something elemental with the tiniest nod of her head. How appropriate: In a bad play about the poverty of language, the one fine moment should be so completely silent.

Until October 8 (2162 Broadway, between 76th and 77th streets, 212-352-3101).