One of the major new changes that were dropped was the introduction of gym raids.
All around the world you there will random raids that will be triggered at any random time, now these raids can only occur at previously known gyms. When a raid starts all the defending Pokémon in the gym would be cleared making way for a monstrous Pokémon.
A huge Pokemon Egg will pop up on top of the gym with a counter on it. As soon as the counter reaches zero the giant egg reaches zero. The raid Boss Pokémon will be revealed. Now, these gym raids have been designed for co-op gameplay.
You will have to take down the raid boss which will be an extremely powerful Pokémon. For example a 25.3K CP Tyranitar. Now you will have to beat this raid boss by teaming up with other trainers a maximum of up to 21 trainers are allowed per raid.
Ok, now before we go on and start saying spoofers are going to ruin this, guess what?
To participate in a raid you will need to have a raid pass, all trainers receive a free raid pass by visiting a gym and not by any other means. But these are other ways to get a raid pass. One of them is by buying a premium one on the shop.
Going on with the raids, once your arsenal of trainers beat the raids boss, all the trainers will have to beat the raid boss within 5 minutes, once you finish beating it, you will have a chance at capturing that beast.
Also as an added bonus, once you beat a raid boss, you will be able to get special items that you can only get by beating a boss. They are rare candies, golden razz berries and two kinds of Technical Machine.
It is not know what rare candies will do, probably increase your Pokemon’s CP by 40 or 50 points, maybe. Golden Razz berry is going to be a more sweeter version of razz berry that will reduce the hitbox colour by 2 stages. And TMs are no brainers, they will help you customizing your Pokémon’s moveset to one you desire.