With the help of a frilly dress, tiara, and magic wand, your 3-year-old becomes the queen of a magical universe and rides a winged unicorn. When you're asked to taste the pink clouds, you agree that they're a lot like bubblegum.

Your 4-year-old pulls a sheet over his shoulders and runs as fast as he can across the lawn. He's a superhero, out to save the backyard from dragons hiding behind the bushes and find treasure buried in the sandbox.

Parents of preschoolers have a front-row seat to some of the most imaginative theater ever made. These are the "magic years" — when kids imagine grand stories and don’t ask, "But can that really happen?"

Here's why imagination is so important and what you can do to foster these magic years.

How Preschoolers View the World

There's a lot that very young children can’t yet grasp about the world around them. So they "fill in the blanks" and often make up their own magical explanations for how things work.

This time, which peaks during the preschool years, was dubbed "the magic years" by child development expert Selma Fraiberg.

Babies use their senses (touch, taste, smell, sight, and sound) to explore their world. As they develop, they begin to understand how things work ("If I push this button, the pony will pop out of the barn!").

Now, as preschoolers, they take this knowledge and combine it with a growing imagination to come up with fantastical ideas about why and how things happen.

Pretend play lets kids try out new roles for themselves (like superheroes, princesses, dinosaurs, wild animals, or even parents) and allows for creative problem-solving. But it also helps them deal with another hurdle of the preschool years: intense emotions. Baby dolls might be put in "time out" and scolded for actions suspiciously similar to your little one's latest offense. An imaginary friend (who's a bigger troublemaker than your child ever could be) might be dreamed up to help your child deal with feelings of guilt and remorse following a moment of lost control, such as hitting a playmate.

Self-control is a tough skill to learn, and pretend play helps kids practice it as well as play out the frustration it creates.

How Can I Encourage Imaginative Play?

Imaginative play begins in a child's mind. But that doesn't mean parents can't join in. Here are some ways to encourage your child's world of make-believe:

• Go along with it. When young ones leap through the air and tell you they're flying, don't tell them they're only jumping. Instead, feed the fantasy: "Wow, you're so high up! What can you see on the ground? Maybe you should take a rest on that nice puffy cloud." Or even better, start flying with them.
• Choose old-fashioned toys. Blocks, dolls, arts and crafts, and molding clay are all toys that require creativity and therefore spur imagination.
• Limit electronic toys. Whether it's a handheld entertainment system or a "junior" laptop, try to avoid toys that need batteries. Creativity is stifled when the toy, rather than the child, directs the play.
• Readto your child. And while reading, ask mind-opening questions: "If you were the caterpillar, what would you eat?" and "What do you think will happen next in the story?" This not only encourages imagination but promotes language skills and fosters an interest in books.
• Schedule downtime. Make sure kids have free time every day to play on their own. Aside from encouraging creativity, it teaches them to use their own resources to amuse or soothe themselves.
• Limit screen time. When kids watch a movie or even an educational program, they experience someone else's make-believe world instead of using their own imaginations. Young kids also are influenced by ads because they can't tell the difference between commercials and actual programs. The same goes for digital ads in online games and apps. Limit screen time (which includes TV, DVDs, computers, smartphones, and tablets) to no more than 1 hour of quality programming per day for kids 2 to 5 years old. When your child does use a screen, take time to watch together.

When the Magic Ends

The day will come when the princess tiaras collect dust and your little ones no longer believe they can fly. It's a bittersweet moment. You'll miss glimpses into that world where anything is possible. But it's a sign that your child is growing up.

The prefrontal cortex — the area of the brain just behind the forehead — has made the connections it needs to process more high-level thinking. So, the way a child thought the world worked is now not necessarily how it actually does work.

Take, for example, vacuum cleaners. A 2-year-old might fear that, just as the dog hair got sucked up off the carpet, he will too. But a year or two later, he might pretend he's being chased by the vacuum "monster" — and gain confidence from knowing that it will never get him.

By age 6 or so, kids are becoming aware that fears like being swallowed up by a vacuum are irrational — there's no way your entire body can be sucked up that little tube and vacuum cleaners are not monsters! Instead, they might want to take control and do the vacuuming on their own. This scenario will be repeated again and again as a child learns to tell the difference between the possible and the impossible.

This is also a time when your fantastical answers to their increasingly complex questions will no longer cut it. Thunder can no longer be a bowling match in the sky and the moon definitely isn't made of cheese. But even though your kids don’t believe these tall tales anymore, it doesn't mean they can't imagine a bowling match in the sky or a moon made of cheese — it just means that now they'll be in on the joke.