Concerned because you can't pry your daughter away from Minecraft? Worried that your son spends every moment obsessing over moves in the super-popular video game?
Chill. It turns out that Minecraft builds up brain cells instead of dissolving them.
Minecraft isn't about bloody broadswords and burning rubber. It has no complex story lines or gorgeously rendered images of alien soldiers. Instead, it's filled with people, animals, trees and buildings that look as if they were built from digital Legos. In a way, they were. The Minecraft universe is made up of blocks representing materials such as dirt, trees, stone, ores and water. Players mine and then use these blocks to craft the shelters, tools and weapons they need to protect themselves against nightly attacks from monsters called "mobs."
When they move beyond the basics, kids can let their imaginations run wild, creating worlds with transporters, flying chickens or rain that springs up from the ground.
Along the way, Minecraft's young players learn things like computer coding, engineering, architecture, urban planning and math.
"I just love the programming aspect. It allows you to change the game itself," says Aiden LaFrance, a 10-year-old from Raton, New Mexico, who has been playing Minecraft since he was 6. Aiden's latest project is a portcullis -- the defensive gate that protected medieval castles -- that rises automatically when a character walks in front of it. He details his work on YouTube, complete with an explanation of how double-piston extenders and a torch tower make it work.
"I would love to be a programmer," says Aiden. "I see Minecraft as helping me get there."
Minecraft offers two basic ways to play. In survival mode, you mine raw materials like trees and coal, and then craft shelter and light so you withstand the mobs' nightly onslaught. Creative mode, by contrast, lets you build without limits so you can devise architectural whimsies like flying castles or interactive constructions, such as booby traps for capturing the bad guys.
Minecraft has lots of ways for people to create some pretty sophisticated machines and scenarios. One of the first is with "redstone," a material that carries electrical signals that activate all sorts of if-this-then-that actions -- like opening a door when a character steps on a pressure-sensitive plate or triggering a piston to push a pumpkin onto an assembly line when it grows big enough. Most impressively, logic circuits built of redstone can form a working computer inside the Minecraft world.
Kids pick up more advanced computer skills through Minecraft's "command blocks" -- code that changes the rules of the game. That can be anything, from altering the weather to generating an invincible flying squid.
"Because there's no overt goal, no immediate plot, no structure, you have the flexibility and freedom to do what you want," says Jeff Haynes of Common Sense Media, which rates software and games for age appropriateness and gives Minecraft a top "learning" score. "It fosters life skills like creativity, curiosity, exploration and teamwork."
Swedish developer Mojang released Minecraft in 2009. Since then, the game has attracted more than 100 million registered users. So far, more than 70 million copies have been sold for Windows PCs and Apple Mac computers, Xbox and PlayStation game consoles, and mobile devices running Apple's iOS and Google's Android mobile operating systems.
Microsoft was so impressed it bought Mojang in 2014 for $2.5 billion.
Today, educators use Minecraft to help teach everything from science, technology, engineering and math (STEM) to language, history and art. But it's the kids who showed the way, turning Minecraft into a constructive tool by publishing tutorials, sharing designs and code, and helping one another online.
"Minecraft caught everybody off guard," says Johan Kruger, a parent and a programmer known in the Minecraft world as Dragnoz. His YouTube tutorials are watched by more than 129,000 subscribers. "Before anybody knew its power or that it could be educational, the kids already took over and owned the world."
Minecraft-literate kids often run rings around parents wanting to keep up. That was definitely true for Aiden's parents, Garrett and Liz LaFrance, who incorporated the game into Aiden's home-school studies. "He ended up teaching us most of what we know about Minecraft," says his mom.
It isn't so easy for many teachers, either, according to Deirdre Quarnstrom, head of Minecraft Education at Microsoft. "It's something every kid in the class knows more about than they do." Quarnstrom leads a five-person team that advises educators and business partners on using Minecraft in lesson plans and projects.
"We realized very early on Minecraft was being used in ways we hadn't thought of when teachers started bringing it into the classroom," says Vu Bui, Mojang's chief operating officer. "Over time we realized it was much more important than we thought. It was something we should support."
Minecraft can capture young minds at an impressively early age. Take Nathaniel MacVittie, a 7-year-old from Green Bay, Wisconsin, whose grasp of command blocks is helping him learn the Python programming language.
"He was able to understand that a line of code in Python was like a command in Minecraft," says his mom, Lori MacVittie.
Minecraft lets Nathaniel use that programming skill to build on another passion: the adventures of sci-fi hero Doctor Who. "All his crafting and adventures of late are focused on building a Tardis and alternate dimensions," his mom says.
Chris Riley, a programmer in Livermore, California, likes how command blocks allow kids to "learn from doing, not being told." Riley plans to introduce his toddler daughters, Maisie and Ava, to the game to help them learn spatial awareness, creativity, project planning, architecture, engineering and programming. (Now that's what you call child's play.)
Minecraft's most complicated programming is "modding," which modifies the underlying code of the game itself. Built by hundreds of contributors over three years, the most elaborate mod so far is probably WesterosCraft, a massive re-creation (comparable to 500 square miles in the real world) of the "Game of Thrones" fictional realm.
"Modding allows you to manipulate everything about the game -- the way it looks, when the sun rises and falls, whether zombies eat you or give you flowers," says Lindsey Handley, co-author of "Minecraft Modding for Kids" and operating chief at ThoughtSTEM, an after-school computer science education program in San Diego.
At Zaniac, a nationwide after-school program based in Salt Lake City, kids have modded in-game characters to look like their real-world selves. They've also designed raw materials that they cultivate for crafting burritos, says Sidharth Oberoi, Zaniac's president and chief academic officer.
Command blocks and modding only work in the original $27 PC version of Minecraft -- not on the versions for mobile devices, game consoles or Microsoft's Windows 10. But Mojang plans to add the advanced features on all versions.
It's this combination of redstone, command blocks and modding that makes Minecraft's open-ended environment so powerful -- letting players shape and invent just about anything they can think of.
But there can be a downside: obsessive play.
The American Academy of Pediatrics currently recommends limiting "screen time" to two hours a day; and Common Sense Media advises parents to not let Minecraft rule kids' days. Playing Minecraft for 10 or 12 hours on the weekends could hurt their ability to interact with people in the real world.
About 1,350 kids have taken a Minecraft program at Zaniac. They've measured gravitational acceleration by having their characters jump off a building, and they've reproduced their redstone circuits in the real world. "With game-based learning, they don't really recognize they're learning," says Oberoi.
Still, some think Microsoft could make Minecraft even more compelling. Robert Grover, co-CEO of PCS Edventures, in Boise, Idaho, wants a virtual-reality version. "Imagine a student creating a virtual replica of the Great Pyramid of Giza, touring the chambers and experiencing ancient Egypt in a way no textbook can approach," he says.
Microsoft is headed in that direction, showing how people can use its HoloLens augmented-reality headset to overlay Minecraft blocks over their real-world surroundings.
But Minecraft offers plenty to explore without fancy augmented-reality goggles. Kruger re-created paintings for the Tate gallery in London that kids can explore from within. Students at the University of Hull have created MolCraft, where kids fly through gigantic versions of molecules like myoglobin, which delivers oxygen to muscles.
The teaching possibilities seem endless. A special variation of the game designed for the classroom, called MinecraftEdu, is so popular that Microsoft bought it last January.
"Every Minecraft player learns essential life skills like tree punching and good Creeper defense," jokes Owen Hill, director of creative communications at Mojang. "But when used in the right way, Minecraft can help people around the world to learn lots more."
Microsoft will release an expanded version of the game, called Minecraft: Education Edition, sometime this summer.
Regardless of Microsoft's education push, Minecraft remains focused on entertainment.
"We consider Minecraft to be a game used in education, rather than an educational game," Quarnstrom says. "Students are more engaged in lessons when they are also having fun."
This story appears in the spring 2016 edition of CNET Magazine. For other magazine stories, click here.