In just two weeks, Pokémon Go has become the most popular mobile video game - ever.
Thousands of people have gathered across the world, eager to hunt for the pocket monsters - even if it means abandoning their cars in New York traffic.
The players are easy to spot, as they walk around glued to their phones. However, this has a drawback, as many of them are oblivious to their surroundings.
Though a warning sign is posted atop an Encinitas cliff, it didn't stop two young men from climbing over the barriers Wednesday afternoon - and later falling.
One landed 27 metres onto the beach below, and the other got stuck alongside the cliff.
"It took a team of firefighters and lifeguards and special equipment to assemble a cliff rescue rope rig," says Encinitas lifeguard Captain Larry Giles.
"If you're just looking at your phone, looking at your phone walking around, you're not aware and you know you're gonna put yourself into potential situations."
The game led 15-year-old Autumn Deiserroth across a busy street where she was hit by a car.
"Just be careful - look where you're going," she says, tearfully.
Another player was arrested, after she chased a Pokémon into the Toledo Zoo.
However, it's not all bad news. Rangers are offering guided tours through parks, and many parents are happy to see a video game that finally gets their children outside and exercising.