EA has released a new developer diary for SimCity showcasing the game’s multi-city play feature, which the publisher is calling “one of the crowning achievements” in the game.

“With multi-city play, you no longer need to provide all the required city infrastructures in one city,” EA explains. “Build a police station and share your growing police force with the greater region. Have your friend build a fire station in a neighboring city and soon you’ll see their fire trucks putting out flames in your city.”