Rugby is the dance that animates Keegan Theatre’s uproariously invigorating, six-actor/60-character sports saga Alone It Stands. Well, rugby and a bit of tribal warfare, let’s say.

John Breen’s play, hugely popular in the United Kingdom, is a sprawling, mostly comic chronicle of an apparently legendary (what I don’t know about rugby fills volumes) 1978 match between New Zealand’s All-Blacks—a professional team that had just whomped the national teams of England, Scotland, Ireland, and Wales—and a bedraggled Irish club known as the Munsters. The all-but-undefeated Kiwis evidently thought they were doing the locals a kindness just by showing up. Turns out they were, but not in quite the way they expected.

The play begins with Keegan’s cast, attired in the uniforms of the All-Blacks, excecuting a thigh-slapping, foot-stomping Maori war chant (“Ka Mate! Ka Mate! Ka ora! Ka ora!”) as if bent on outright slaughter. At once fierce and funny, this opening moment proves representative of the high-impact, rough-and-tumble evening that follows. In short order, those same six performers morph into the scrappier Irish team, as well as a couple of differently caustic coaches, some local kids building a bonfire, a dog, a woman about to give birth, and a reasonably representative cross-section of the hard-drinking, raucously cheering SRO crowd that crammed into Limerick’s Thomond Park that day.

Actually, even that catalog of characters understates the cast’s versatility; the performers also play a rattletrap of a taxi, a maternity-ward gurney complete with stirrups, and a funeral bier topped by a corpse.

Keegan employed some of the same multicharacter techniques in its more politically pointed two-actor romp Mojo Mickybo (if you’ve not already caught it at the Church Street Theatre, you should), but husband and wife co-directors Eric Lucas and Kerry Waters Lucas take full advantage of their bigger cast in Alone It Stands to expand their storytelling possibilities exponentially. Exploits on the field are accompanied by sportscaster standups, slo-mo replays, cheers from inebriated fans, and soaring Vangelis synthesizers. Tickets are scavenged, scores settled, game films analyzed, and a few dozen characters clearly delineated. By evening’s end, the audience has journeyed to roaring bonfires, noisy pubs, a packed stadium, and at one giddy moment has been taken not just into the middle of a scrum but very nearly into a player’s wife’s birth canal.

Which is not to suggest that the evening is exclusively about movement. John Breen’s script can be rabble-rousing and graceful all at once. Describing one crucial play that will depend on a rugby ball’s utterly unpredictable bounce, he has a character shout “Earthworms and physics determines the outcome; today, the earthworms are cheering for Munster.”

You’ll be, too.