An announcement appears in the Union Chat as soon as one of its members starts gathering a team. Players who apply for the battle will be shown in the windows. Press the "Fight!" button to join. You’ll also see an active horn on the chat's icon as the team gathers.

There's another way to learn about the formation of a team. Open the Snowball Fights interface and click the Union Battle waiting window to join an ongoing waiting list. Remember that you must have enough snow to participate in a battle.

Only the team captain can start the battle. If you’re tired of waiting for the captain to find a game, you can always close the waiting window and leave the team.
If you want to be captain, make sure you have enough snowballs. Then press the icon with the snowball under "Union Battle".

You may enter a battle if at least one ally from the Union joins the team. The new players will be added to the list as soon as they join the team. Your name will be highlighted in color, and a crown will appear over your avatar. If at least three players in your union join the team, it will be deemed a Union Battle.

Two teams of five players participate in a battle. If a current captain closes the waiting window, the second player on the list will be appointed a new captain.