Multiplayer allows you to battle against players from around the word. You'll be matched with players that have a similar number of Scrolls. You can steal gold from opponents by crushing their Gold Wheels and Castle. In order to win any Scrolls, you must earn at least 1 star. Following the same rules as Single Player, you get one star for destroying the Castle, 1 for smashing all of the Gold Wheels, and 1 for reaching the Point Goal.
You can steal a higher percentage of your opponent's gold when he has at least the same Castle level as your Castle level. To steal all of the available gold, you must win in 3 star fashion. However, 1 and 2 star victories still allow you to loot your opponent's gold storage, and you can always take gold from his Gold Wheels without even winning the attack.
The available Scrolls to win are calculated based on your total Scrolls compared to your opponent's Scroll count. If you have fewer Scrolls than your opponent, you're able to steal more, and vice versa. In order to actually win all of the available Scrolls, you need a 3 star victory, although you'll take some Scrolls for a 1 or 2 star performance. You don't lose any Scrolls if your attack is unsuccessful.
If you're on a team, you can also steal Blue Scrolls during attacks. The Blue Scroll theft rules are similar to those of standard Scrolls, but the amount that you can steal is more heavily weighted to your opponent's absolute Scroll total, as opposed to his Scroll count relative to your count. If your opponent has a high number of Scrolls, you can win a lot of Blue Scrolls.