Everything you need to know about Pokémon Go

Pokemon is back, with a new tech twist that is thrilling kids and millennials who fell in love with the pint-sized monsters in older versions of the video and card game.

“Pokemon Go,” released Thursday in the United States, Australia, and New Zealand. According to the Internet research firm SimilarWeb Ltd. 5 percent of the nation’s Android smartphones have downloaded a copy of the game, making it more popular among Android users than the dating app Tinder. SimilarWeb also reports that daily usage of “Pokemon Go” among Android users is already equal to that of the social network Twitter.

It’s a remarkable degree of popularity for a game that requires a major investment of shoe leather as well as time. Instead of hunkering down in an easy chair, “Pokemon Go” players wander the streets, bringing classic Pokemon monster battles into the world of “augmented reality.”

Confused? Here’s what you need to know.

Created 20 years ago by Japanese game designer Satoshi Tajiri, Pokemon is set in a world in which humans discover Pokemon, or “pocket monsters,” odd alien beings with remarkable powers. People capture these Pokemon beings, and train them to fight one another. Pokemon is now a global media empire, featuring TV series, movies, and of course a number of hugely popular video games produced by Japan’s Nintendo Co.

“Pokemon Go” was created by Niantic Inc., a company spun off from the giant Internet search and advertising company Alphabet Inc., better known as Google. Niantic was founded by John Hanke, who also started Keyhole Inc., a digital mapping company that Google purchased in 2004 and transformed into Google Maps.

In “Pokemon Go,” players wander the neighborhood, smartphone in hand, following a cartoon-like but very accurate street map. They’re looking for “Poke Stops,” nearby landmarks where they can receive special rewards that help in playing the game, such as eggs that can hatch into Pokemon creatures. Poke Stops are also a good place to hunt for newborn Pokemon monsters, though these creatures can randomly appear just about anywhere on the map.

The game uses augmented reality software to project the creature’s digital image onto video from your phone’s rear-facing camera, generating the on-screen illusion of an alien being come to life. Touch the creature’s image, and it seems to leap into reality, squirming, bouncing, or leaping on the sidewalk in front of you, on a park bench, or on a subway platform.

In classic Pokemon style, your job is to capture the creature inside a red-and-white “Poke Ball,” add it to your collection, and train it to win battles against similar beasts captured by other players. It costs nothing to play “Pokemon Go,” but like other “freemium” games such as “Mobile Strike” or “World of Tanks,” players can quickly become stronger by purchasing special tools and powers through the game’s built-in retail store.

Still, you can’t begin to fight other creatures until you’ve become a “Level 5” player. And you can only manage that by spending hours wandering the world and collecting Pokemons. If you’re less than obsessed, it gets a bit tedious. But on the upside, you’ll get lots of exercise.

For an additional workout, you can start hatching any eggs you’ve collected. Plug them into the game’s incubator, and get moving. Some eggs require you to walk -- or run -- about 1.25 miles, while eggs that produce more powerful monsters require a greater distance to hatch -- for instance, just over three miles.

All showdowns take place in battle arenas called “gyms.” Like the Poke Stops, they’re found at random locations around town, usually some well-known landmark like a church, subway station, or public park. There are friendly gyms where you can ally with your buddies to control the gym and fight off challengers, as well as hostile gyms that you and your friends can try to conquer.

But you can only play when you’re within a hundred feet or so of a gym. So “Pokemon Go” is a game for playing when you’re out and about. It’s not intended for unattended children, but ideal for mobile millennials who grew up on Pokemon games and cartoons.

Early adopters have stumbled across technical problems aplenty. The game’s so popular that the back-end servers that control the action have been known to crash at odd moments, and attempts to capture new creatures end with ugly red error messages.

“Pokemon Go” makes big demands on the smartphone’s data connection, camera, GPS location chip and videoscreen. So playing for a couple of hours could easily drain your battery.

In addition, it’s not always easy to find places to play. “Pokemon Go” uses landmarks from a previous Niantic game called “Ingress” and hasn’t set up enough new hotspots for Pokemon buffs. A player in Boston may have to travel for many blocks to find a target-rich environment; imagine what it must be like for a Pokemon buff living in Kansas or Idaho.

The new game also raises privacy questions. Like nearly all freemium games, “Pokemon Go” tracks the player’s every move through the real world, and the company reserves the right to use this data to target you with relevant advertising. For now, no ads appear in the game.

In addition, if you sign up for “Pokemon Go” on an Apple iOS device and log in by using a personal Google account, Niantic gets full access to all your stored Google data. That gives the company the ability to read your e-mails of the files you’ve stored in Google Drive. That makes “Pokemon Go” far more intrusive than most other apps. It’s unclear why the company wants so much data from its users, but Niantic did not respond to phone calls and e-mails seeking an explanation.

Then there are the safety hazards. The game allows players to purchase “lures” that can attract Pokemon creatures and real-life players to particular locations. Already, police in O’Fallon, Mo., say they’ve arrested a band of armed robbers who used game lures to attract multiple victims. And of course, careless players may wander into traffic while staring into their screens.

Still, the popularity of “Pokemon Go” proves that millions who grew up waging endless Pokemon battles are as avid as ever, and eager to take the fight outside.