The phenomenon that is Pokémon Go first launched on mobile almost twelve months ago and this Summer it's getting a massive update as developer Niantic adds co-op multiplayer and changes the way gyms work, quite drastically.

Multiplayer raids are one of the major new features coming to the game — public and private raids will be available. Basically, it allows a player to join up to 19 others in order to defeat a larger, tougher boss. These bosses will pop out of eggs that appear at the various gyms across the map. Once they hatch, players will have five minutes to defeat the powerful Pocket Monster, and then capture it in a Pokéball.

You can also earn a whole host of new items through raids: Golden Razz Berries, which help catch wild Pokémon; Rare Candies, which become an extra candy when used on a Pokémon; Premiere Balls that enable you to catch the boss Pokémon; and Charged and Fast technical machines, which give you the opportunity to teach one of your Pokémon a random new move.

Gyms are also getting overhauled. Instead of the three that you're used to, Pokémon Gyms will now be the home to six Pocket Monsters of varying type. They'll also have this thing called motivation factor. Effectively, you must keep Pokémon who are on your team content by feeding them berries, and thus making them more difficult to beat. If you're battling them, you'll face off against Pokémon in the order that they were placed there, rather than take on the weakest first. Gyms will also now act as regular Pokéstops too, allowing players to spin a disc to pick up some additional items. 

Niantic has said that the update will be available soon, but in the meantime is disabling gyms. Speaking to The Verge, the dev said 'once the update has been rolled out to players around the world, gyms will return.'