Friends

You can add and view your friends by going to the friends menu.

Share your Player ID so you can be added as someone's friend. You can also remove friends by going to the remove tab.

Tapping on the status icon will let you challenge them to a battle.

Friendly Matches
When you challenge a friend to a match, you will be met with a screen allowing you to customize several aspects of the match.

Some customization options require you to have a certain Fortress Level to change. Note that these restrictions only apply when sending a match request; Fortress Level 10 players can accept customized matches from Fortress Level 20 players just as fine as any other match.

The customization options are:
 * Card Level Cap: the maximum level players' cards will be during the battle. No Fortress Level requirement.
 * Base HP Cap: the maximum health players' bases will be during the battle. No Fortress Level requirement.
 * Starting Mana: the number of mana at which players start the game with. Requires Fortress Level 14 or higher.
 * Turns per Player: the number of turns each player has until the game forces an end. Requires Fortress Level 16 or higher.
 * Custom Rules: any Brawl Mode modifiers that will be active during the battle. Requires Fortress Level 17 or higher.