A year after Pokémon Go captivated the world with its location-based catch-athon, Niantic is making some changes. The biggest is raid battles, a concept that was teased in the very first trailer for the game. They'll launch "in the coming weeks" and take place at existing gyms, allowing groups of players to take on rare and powerful Pokémon together. At first, you'll see an egg and a countdown timer, as well as one to four boss icons which indicate the creature's difficulty. When the meter drops to zero, the Pokémon will appear and you'll have a limited time to catch it.