Daddy Tyl: The same things that make trouble everywhere. Greed. Selfishness. Those who aren't content with what they have.
Mytyl: But you're not like that, Daddy. Why should you have to go?
Daddy Tyl: That's what's wrong about it, Mytyl. You can't be unhappy inside yourself without making others unhappy, too.
This play contains examples of:
- And You Were There: The same actress plays both the children's mother and the Spirit of Maternal Love. The 1976 version expands on this by having her actress also play Berylune (referred to in the credits as "The Witch") and Light.
- Anthropomorphic Personification: Most of the characters are these, representing concepts, objects, or animals.
- Breaking the Fourth Wall: At the end, Tyltyl does this to ask audience members to — if any of them should find it — return the Blue Bird to him and the sick girl.
- Cats Are Mean: Tylette. She does not like being in thrall to mankind, and tries to encourage her cohorts to keep the children from fulfilling their quest to find the secret of happiness because that would only put animals, etc. further under Man's control. When that fails, she collaborates with Night and later the tree spirits to stop the children.
- Chekhov's Gun: The big one turns out to be the children's pet bird. Less importantly, the children's father is a woodcutter, and the tree spirits of the forest — already bitter with mankind's dominance over them — are not happy to meet them as a result.
- Dark Is Evil: Night is the keeper of the world's secrets (both good and evil), and does not want Man to know the secret of happiness. With this in mind, she tries to scare the children and their companions away with some of the nastier things she keeps under lock and key, including ghosts, wars, and diseases. And Death can be seen sleeping at her feet.
- Everything Talks: Once their spirits are revealed, anyway. Animals, trees, food, you name it!
- Fairy Tale: A theater example, and an original story to boot.
- Female Feline, Male Mutt: Tylette and Tylo, respectively.
- Idle Rich: All the Luxuries do is enjoy parties and feasts in their palace.
- It Was with You All Along: Justified: Their pet bird was black before the children set off, but after they're "en-Lightened" to what's truly important in life (as critic John Simon put it), they return to find it's turned blue.
- Light Is Good: And she is the leader of the sidekicks.
- Loads and Loads of Characters: The kids get eight sidekicks, for starters!
- Or Was It a Dream?: The final scene reveals that the children's year-long quest for the Blue Bird is a dream that unfolds over one night, but not only is their neighbor Berylune's daughter actually ill, their pet bird is now blue....
- Shoot the Shaggy Dog: The poor kids finally get the Blue Bird only for it to fly away almost as soon as they give it to the sick girl!
- Star-Crossed Lovers: Two children-to-be have fallen in love in the Kingdom of the Future, but one isn't due to be born yet and has to watch as their sweetheart heads down to Earth without them. (They hope to find each other someday.)
- Theme Naming: With one exception, the names of every character contain the syllable "Tyl" at least once.
- True Beauty Is on the Inside: One of the big Aesops. The diamond's ability to reveal the true nature of things allows Tyltyl and Mytyl to see just how beautiful things they take for granted or fear actually are, starting with the old crone being revealed as a beautiful fairy. Maternal Love resembles what their mother would look like if she weren't weighed down with the day-to-day responsibilities of running a household and raising kids, and The Land of the Dead initially looks like a graveyard but turns out to be a beautiful garden of peaceful departed souls. The children, once they return home, take this lesson to heart and can see the beauty of their surroundings and family without the diamond.
The 1940 version includes examples of:
- An Aesop: "We'll find it again because now, we know where to look for it, don't we?"
- Big Fancy House: The Luxurys' mansion.
- Cats Have Nine Lives: Mytyl uses this to explain why Tylette is waiting back at the house after being burned to death in the forest.
- Chekhov's Gun: In this version, the bird Mytyl catches at the beginning turns out to be the Blue Bird.
- Deliberately Monochrome: Until the children's dream begins. The rest of the film is in color, even when they return to the real world.
- Disney Death: Tylette, who still has eight lives left.
- Follow the Leader: This was 20th Century Fox's answer to The Wizard of Oz.
- In The Future Everyone Will Be Famous: When they go to the land of tomorrow, they meet the unborn versions of several famous people, including Abraham Lincoln.
The 1976 version contains examples of:
- Billing Displacement: Tyltyl and Mytyl (Todd Lookinland and Patsy Kensit) are billed ninth and tenth in the opening credits, and after the title to boot. Moreover, while Elizabeth Taylor's top billing makes sense (given her Loads and Loads of Roles and their relevance to the plot), and U.S. viewers of the time would certainly recognize her fellow American actresses in important supporting roles, the four Russian performers credited before the title all play much smaller roles. (Oleg Popov, as "The Clown" at the Palace of Luxury, is just The Cameo played up because he was the star of the Moscow Circus well into The Eighties.) Given the nature of the production, this was probably mandated so that the Russian side of it would not be marginalized.
- Canon Foreigner: Luxury, Ava Gardner's character. Like the play's Luxuries she embodies a particular indulgence, but unlike them which one it is isn't revealed. (See Femme Fatale below for more on this issue.)
- Color-Coded Elements: Reflected in several characters' costumes.
- Light: White
- Night (dark): Black
- Fire: Red
- Water: Blue
- Composite Character: Here, the old crone Berylune (called "The Witch" in the credits) is revealed to be Light herself, rather than a fairy.
- Costume Porn: Elizabeth Taylor (as Light), Jane Fonda, and Ava Gardner all get glamorous costumes.
- Everything's Better with Sparkles: Light's gown, tiara, and wand, as well as Night's elaborate hat.
- Everything's Sparkly with Jewelry: Luxury.
- Femme Fatale: Luxury is this to Tyltyl — she ends up diverting the whole party from their quest when she convinces him to come with her to the Palace of Luxury and enjoy the fun and food there. It's clear he finds her attractive, and when he asks her which specific luxury she happens to be (after she introduces him to ones like The Luxury of Eating When You Are Not Hungry and The Luxury of Knowing Nothing), she tells him that he'll find out when he's older. She even dresses in red; while her gowns are not typical of the Lady in Red trope, the symbolic function of the color is clear.
- Gem-Encrusted: Luxury and her cohorts' costumes.
- Grief Song: "Wings in the Sky" for Light when the children realize, to their sorrow, that the (fake) bluebirds they caught in Night's castle have all died.
- Let's Mock the Monsters: Mytyl and Tyltyl are initially afraid of the ghosts in Night's castle, who resemble decaying Elizabethan actors and moan their way through Shakespeare. But when Tylo barks and paws at them to defend his masters, the children realize the ghosts are capable of being scared too. They find this funny and from there easily drive them back behind their door.
- Loads and Loads of Roles: Four for Elizabeth Taylor (technically three, due to the Composite Character issue).
- Man in White: Both Sugar and Father Time.
- The Musical: There are both songs and dance interludes, the latter showing off some of Russia's top ballet dancers of the period.
- No Song for the Wicked: None of the villainous characters get to sing or dance.
- Pan Up To The Sky Ending: One that has the Blue Bird in flight.
- Raven Hair, Ivory Skin: Light.
- Rhymes on a Dime: Most of Fire's dialogue. Light, Water, and Bread each have rhyming speeches when they are first revealed, but Fire speaks almost exclusively this way.
- Setting Off Song: "Blue Halloo", a song about finding and sharing happiness, though it's placed after the kids have made their first stop in the Land of Memory.
- Woman in Black: Night. Tylette was supposed to be this as well, but actress Cicely Tyson (an African-American) didn't like the implication of "black = evil", so instead she wears brown.
- Woman in White: Both Light and Milk; Light's dress is sparkly while Milk's is simple and homey.