Starting today, Pokémon Go players around the world can start battling against each other online. Called the Go Battle League, the new system adds a much requested feature to a game that first launched in 2016.

Niantic said today in an official blog post that Go Battle League will begin to roll out gradually to high-level players starting Jan. 28. First up is a “preseason” period, during which the developer will “optimize and balance” its systems.

“We will also be taking this time to learn about how the Go Battle League is being used in order to determine things like ideal length of seasons, rating thresholds for ranks, and more,” Niantic continued.

Pre-season will begin with the Great League, then move on the the Ultra League (Feb. 10), before concluding with the Master League (Feb. 24). The Great League will return again on March 9.

Players who participate in Go Battle League will receive in-game rewards based on their rank and the number of wins they achieve. Those rewards will include Rare Candies and exclusive Pokémon encounters (like Scraggy).

A complete rundown of all the possible rewards has been datamined and was detailed by Twitter user @poke_miners:

Some changes to the rewards for GO Battle League overnight (already reported on Discord and Reddit; the Twitter guy was sleeping ).



Changes in the next tweet!



High Res: https://t.co/cDyYbeg8Us pic.twitter.com/wjnpE4n804 — PokeMiners (@poke_miners) January 28, 2020

For more details check out the official announcement.