Here's how Raids work in Pokémon Go

As you're walking through your neighbourhood catching Pokémon in Pokémon Go, you may have seen a suspicious egg sitting on top of a local Gym with a timer counting down above it. If the timer is close to zero, head over there immediately; a Raid is about to begin.

This guide will walk you through everything you need to know about Raids in Pokémon Go, from the types of Pokémon that you'll see to the best ways to take down the Raid Boss in question. Raids are the only way to find some of the most powerful Pokémon in the game, so be on the lookout. You may just find your next Legendary encounter.

Raids are Pokémon battles that happen periodically in Gyms throughout the world. A Boss Pokémon will hatch out of an egg on top of the Gym and the Raid will be active for a short time.

The Pokémon that appears from the egg will be assigned a rank between one and five based on its difficulty. You'll be able to tell the difficulty of a Raid based on the egg that appears on the Gym. The more difficult a Raid is, the more powerful the Raid Pokémon will be, and defeating the most powerful Raids will yield incredible rewards.

You can find Raids simply by looking around the map in your area. If you see a Gym with an egg on top, you'll know that a Raid will be taking place there soon. If a Pokémon and timer appear on top of the Gym, then a Raid is already in progress.

You can also find Raids in your area by tapping the Nearby menu on the bottom-right corner of the main screen, then selecting the Raid option. From there, if you tap on one of the listed Raids, its location relative to you will appear on the map and you can plan a route there if you wish.

The main way to join a Raid is to be in the immediate area of the Gym hosting the Raid and be in possession of a Raid Pass. You can get a Raid Pass from spinning the Photo Disc at a Gym or by purchasing them from the shop. From there, submit your Raid Pass to create a new Raid session.

The more difficult a Raid is ranked, the more powerful its Boss Pokémon will be, so you'll need to enlist some help in order to win. Once you start a session, other players can join you for the next two minutes before the Raid begins. You can invite as many as five friends for a Raid or be matched with random players.

Taking down a Raid Pokémon will give you and your team members experience and items – including Premier Balls – as rewards. You'll also get the opportunity to catch the Boss Pokémon that you defeated using those Premier Balls.

If you’re successful in catching the Raid Pokémon, it’ll be added to your Pokémon Storage. However, if you run out of Premier Balls before catching the Pokémon, it’ll flee, and you’ll miss your chance for that particular Raid. Use the Premier Balls as carefully as possible and you should be able to catch that five-star Legendary Raid Pokémon when the opportunity arises.