It used to be that if you saw someone wandering around obliviously staring into the mobile device in his hand, you could be pretty sure he was absorbed in an engrossing ebook. But now people have a brand new reason to stare at their phones. Pokémon Go has gone live, and gone big in a major way. So many people have started using it that Niantic had to pause the international roll-out until it could make sure it had enough servers in place to handle the rush.

Google Play ranks Pokémon Go as the number one free game, and the number two top-grossing game (due to in-app purchases). It’s also at the top of the iTunes free apps chart. That’s a lot of people wandering around staring at their phones—enough that, if you see people displaying that behavior pattern in public right now, odds are pretty good that if you go up to them and say, “Pokémon?” they’ll say yes.

We Ingress players used to joke about being able to do that for our game, but our game wasn’t based on a 21-year-old mega-fad franchise. I’ve already met several other Pokémon Go players in real life, and none of them had been interested in Ingress beforehand—though they did get interested when I explained that Ingress has an area map of where the greatest concentrations of stuff are, whereas Pokémon Go doesn’t seem to yet.

I’m not sure that a blog post going into detail about how the game is played would necessarily be on topic for even the notably less strict dot-org version of TeleRead (perhaps I’ll do something about it for my personal blog instead), but one thing that’s worth mentioning is that the game basically requires a smartphone’s undivided attention.

Part of how it works is to count the distance you’ve walked, because hatching Pokémon “eggs” requires two, five, or ten kilometers of cumulative hiking. And the app can’t keep track of your movement unless it’s in the foreground and the device is not sleeping. Also, it can only alert you when you pass near a Pokéstop or a randomly-spawned wild Pokémon with sound if it’s on. So, you have to get used to leaving it active and running. There’s even a “battery-saving mode” which mostly blanks the screen when the device is upside down. So you simply stick it upside down in your pocket and keep moving, while it keeps draining your battery and keeps you from doing much else with your phone.

I wasn’t able to get Pokémon Go to run on my Nexus 6 because it’s not compatible with the Android N beta, but it turns out that running it on my old Republic Wireless Moto X tethered to my Karma Go hotspot is a blessing in disguise—I can do other things with my primary phone, including running Ingress or keeping it asleep most of the time to save battery power.

I’m not sure that requiring your phone to stay on and active at all times for use is necessarily a good idea. If nothing else, it means you can’t read ebooks while you play—though audiobooks might just be an excellent choice for an extended Pokémon Go session (though they will tend to keep you from being able to interact with other people). Either way, at least it’s getting people outside (even if some of them aren’t necessarily best prepared for the exercise!). But you’d better invest in some USB battery packs if you plan to play seriously!