Exclusive Raid or better known as EX Raid is a type of raid that is by invitation only. The EX Raid will periodically appear at gyms around the world and invitations are sent out to the Trainers to join the raid on a specific time. An EX Raid pass will be issued to Trainers prior to the EX Raid to remind the Trainers on the date and time of the EX Raid.
To receive an invitation to participate in an EX Raid Battle, Trainers must have successfully completed a raid recently, by defeating the Raid Boss, at the Gym where the EX Raid Battle will be taking place. The invitations will include advance warning of when the Exclusive Raid will take place, giving them ample time to coordinate with other Trainers before taking on the powerful Raid Boss.
Trainers who complete more Raid Battles (at any location) the week before EX Raid Battle invitations are sent will now have a greater chance of being selected. Furthermore, trainers with a higher level Gym Badge on the EX Raid eligible Gyms are now even more likely to receive an invitation for an EX Raid Battle on that gym.
The Gyms that meet the necessary criteria for an EX Raid Battle are marked as EX Raid Gym. This can be easily spotted in the gym on the top right of the gym information. You can also search through the EX Raid Gyms using the Gym Search.