In 2v2, the King's Tower has two cannons, is wider, has 2 Kings, has a special badge with two Crowns on it and it has about 20% more health than an equivalent level King's Tower. Both cannons have their own individual range. The Princess Towers remain unchanged.
There are no level restrictions in normal 2v2. The level of the Crown Towers is the average of the two players' individual Crown Tower level, rounded up or down if necessary.
Both players use separate decks. Elixir generation is slowed to 85% of the normal generation (roughly 1 Elixir every 3.3 seconds). During Double Elixir and Overtime, Elixir generation is decreased to 70% of the normal Overtime generation (1 Elixir every 2 seconds).
At the beginning of the battle, players can briefly see their teammate's deck, and during the battle they can see the teammate's current cards in hand by tapping and holding on the teammate's name. It is possible to work out how much Elixir the other player has by looking at how greyed-out their cards are when their name is tapped. They will also see where their teammates are hovering their cards. Because of this, it's beneficial to deploy cards by dragging rather than tapping.
All spells affect both players of a team. For example, a friendly Rage or Heal would enrage or heal all friendly troops within radius, including a teammate's. Similarly, an opposing Freeze or damaging spell would freeze or damage both teammates' units. However, an Elixir Collector will only generate elixir for whoever plays it.
The arena space behind a King's Tower is expanded, to have more space for deploying troops. However, there is less space between the sides of the King's Towers and the edges of the Arena.
Clan Battles were a special event which started with the Clan Battle Chest.
Clan Battles were triggered by a special button on the top-right corner of the Clans screen.
They worked like 2v2 Friendly Battles in the sense that they didn't drop rewards and were at tournament standard. Clan Battles, however, were played with a member of the same Clan against two opponents from a different Clan.
Winning a Clan Battle would award one Clan Battle Win to the Clan Battle Chest, no matter how many Crowns were taken.
The Clan Battle Chest was a type of chest belonging to a clan. It was similar to a Clan Chest in the sense that clanmates needed to co-operate in order to open it.
The Clan Battle Chest started every other Friday. All players in a Clan at the time had the opportunity to gather Clan Battle wins for the Clan Battle Chest.
Players were able to gather Clan Battle wins for three days. They would attempt to gather as many wins as possible in order to maximize the rewards for the Clan Battle Chest.
Once the players had enough Clan Battle wins for the maximum reward, or the three-day Clan Battle Chest event had elapsed, the Clan Battle Chest was be available for opening. The amount of Gold and cards offered do not differ between players, but its contents will differ depending on the Arena the player is in. For example, a player in Arena 7 will not be able to obtain cards from Arena 8 through the Clan Battle Chest.
The total number of wins was tallied in the Chest tab of the Clan info screen. There, players were ranked based on the number of wins the player had contributed. For this purpose, a Clan Battle win was shared between the two winning clanmates, so each win awarded both winning players with half a win each.
To earn the rewards from the Clan Battle Chest, a player must have remained in the Clan for the duration of the three days and must have contributed at least half a win to the Chest. A player that had just joined the Clan must have waited until the next Clan Battle Chest was available, regardless of any previous contributions.
If a Clan had earned the maximum reward, players could still play Clan Battles but without further rewards. Players with zero contribution were still ineligible for the Clan Battle Chest, even if they had contributed after that.
The mode of 2v2 was first introduced as Clan Battles. The first Clan Battle Chest event started on 24/3/17.
On 3/4/17, a maintenance break increased the requirements of wins by 150%. The sizes of the Clan Battle Chests stayed unchanged.
On 12/6/17, the 2v2 mode was expanded, adding a temporary 2v2 button adjacent to the normal Battle button, allowing players to play matches with players from outside the player's Clan, as well as the player's friends from the Friend list. This mode of play also allowed play with clanmates as it did previously, and allowed players to obtain Chests without playing 1v1 Arena matches. This feature lasted for a week, as a probationary test for 2v2.
This 2v2 mode no longer uses friendly rules; Crown Towers and Card levels are no longer adjusted to tournament standards.
This update unified the Clan Chest and the Clan Battle Chest, as both ladder matches and 2v2 matches contribute crowns to the Chest. If two players from the same clan pair up, the crowns they gain count for both players, resulting in double contribution.
On 30/6/17, the 2v2 button was made available for the entire month of July, retaining the same functionality as it did in the earlier probationary period. This allowed players to play 2v2 matches outside of Clan Battles. This button was then removed on 1/8/17.
On 21/8/17, the 2v2 mode was made available outside of Clan Battles once more, this time on a permanent basis.
The n-th tier of a Clan Battle Chest required wins total and rewards Gold and cards.