Players can form an Alliance to chat with each other, support each other, share their strategies and fight alongside one another in rallies. To join an Alliance you need to either apply to one, or join an open Alliance. You can do so by tapping the "Allies" button in the bottom menu:
You can choose to join an existing Alliance from the list of suggestions that will be shown to you there. You can also search for a specific Alliance, using its name or tag. You can also refine your search further by limiting results to a specific "working language" of the Alliance you are looking for.
Some Alliances will be open and you can become a member immediately without sending a request. Other Alliances will require manual approval by their leaders.
To join an open Alliance, just select it from the list, and use the "Join" button:
Note: You can only be member of a single Alliance at a time. If you want to join another Alliance, you have to leave your current one first.