Tens of thousands of Pokémon trainers will be descending on New York City this weekend in their never-ending quest to "catch 'em all."

Beginning Friday, players of the popular mobile game Pokémon GO from developer Niantic will spend three days scouring both the Big Apple and nearby Randall's Island Park for Pokémon creatures during the Pokémon Go Fest.

Organizers expect 70,000 people to attend the event through Sunday, Pokémon GO's largest public event since the augmented reality game launched seven years ago as a mobile phone app.

But the large crowd won't be the only thing setting apart this weekend's festivities from a typical hunt. Attendees will also be offered with the chance to catch rare Pokémon, such as the mythical Diancie.

"Pokémon GO is all about playing together," Niantic CEO John Hanke said in a statement to USA TODAY. "This event is a chance for people from all over the world to come together with their friends, family and other trainers to play and connect with new people who are equally enthusiastic about the game."

Here's what you need to know about the massive festival:

Are you a robot?Study finds bots better than humans at passing pesky CAPTCHA tests

What is there to do during the Pokémon GO Fest?

Diancie may be considered the "crown jewel" of the festival, but plenty of other Pokémon will also be making a special appearance in the wild for trainers to capture.

As the main venue for trainers, Randall's Island Park has been festooned to look like a habitat replete with volcanoes and poisoned swamps where wild Pokémon run free. Participants can battle one another and join in a variety of other challenges that include both collecting and researching these rare creatures.

Within the city itself, Pokémon GO trainers will use their mobile app to navigate around all five boroughs in search of their quarry.

All told, trainers will be able to catch more than 50 different Pokémon species, some of which are being released in New York City before anywhere else in the world.

How much are tickets?

Tickets can be purchased for $30.

A variety of add-ons are also available for additional fees that include an exclusive T-shirt and access to upgraded perks, such as more experience points for completing challenges.

Trainers who buy a ticket will split their day between exploring Randall’s Island Park and adventuring throughout New York City. Every ticket includes both the Randall’s Island Park and New York City experiences, with the only difference being the time of day guests visit each location.

What are the hours of the festival?

The event lasts from 9 a.m. to 7 p.m. ET each day.

While the citywide experience is available all day between those hours, ticket-holders will only be able to visit Randall's Island Park during the hours listed on their ticket: Either 9 a.m. to 1 p.m.; or 3 p.m. to 7 p.m.

Direct sequel:Video game trailer reveal for 'Call of Duty: Modern Warfare III', out Nov. 10

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected].