WHAT: Being spontaneous

WHERE: ImprovBoston

WHO: Globe staff member Milva DiDomizio, daughters Claire (15) and Abby (13),

friends Ezra (15) and Kay (14)

You know those performances your kids stage in the living room, where they make everything up as they go along? The ImprovBoston Family Show is a lot like that, except the players are grown-ups remarkably skilled in the art of on-the-spot entertainment.

Milva DiDomizio for the Boston Globe

Actors on stage during the ImprovBoston Family Show.

On the night we went, the performers were five women and one guy with a guitar who sat off to the side strumming away, providing background mood music or accompaniment to one of the songs the actors composed out of thin air.

At the start of the show, a troupe member asked if anyone knew the meaning of the word improvisation. A young boy answered, “A play with no script.”

“Bingo!” the actor cheerfully replied.

Next question: “What would you like to see a show about today?”

“Dolphins,” a little girl shyly requested, and the actors were off and running with a song that sounded like it would be titled “Jumping Out of the Sea.” In the sketches and songs that followed, the dolphin picked up a name (Amanda), and ended up starring in a story about two fourth-grade girls, their mothers, a villain called the boggan who steals Trapper Keepers (a kind of loose leaf binder), and a wise janitor named Steve who reveals the bad guys’ weakness ­— song and dance.

Like all good actors, they used body language, facial expressions, and vocal fluctuations to portray different characters. This was impressive, given that none of them knew who those characters were until they were onstage. Even more impressive was their ability to weave the strands of the various sketches and songs into a surprisingly layered plot. Their pacing was good, too. They kept things moving, and despite the spontaneous script creation, there were very few missteps. On the contrary, many jokes were bull’s-eyes, generating belly laughs and guffaws aplenty.

During the show, willing kids from the audience were invited onstage to participate. In one sketch, a little girl and boy sat on black wooden blocks while two actors created a scene using their input. It was a fill-in-the-blank kind of thing, with each child being asked to contribute a word to finish a thought, like a Mad Libs story enacted onstage.

In another participatory segment, one of the actors left the theater while audience members helped fashion a party scene by volunteering the name of a famous person (David Tennant a.k.a. “Doctor Who”), a person with an unusual ability (shapeshifter), a historical figure (Genghis Khan), and the reason for the party (a pet’s birthday).

The actor was then summoned, and with audience encouragement and clever clues from her fellow performers (the shapeshifter: “I feel a triangle coming on!”), guessed each of the categories in a sketch that played like a game of charades without the restrictive rules.

Don’t be surprised if the performance inspires your kids to want to put on their own shows. Fortunately, they don’t have to limit themselves to the living room. ImprovBoston offers classes for youth that nurture confidence, team building, and improvisation and communication skills.

ImprovBoston Family Show runs Saturdays at
6 p.m. $14, $8 under 12. ImprovBoston, 40 Prospect St., Cambridge. 617-576-1253, www.improvboston.com