Because of the addition of other new defensive buildings, the original formation was no longer applicable, and a number of seven formations were extended beyond the six books. The double-back array is one of them, through the clever arrangement of anti-aircraft lineups and built-in traps, making the conquest of this formation very difficult, the emergence of a large number of walls in seven books also allows this formation to have enough space to reserve traps, further increasing the difficulty of enemy conquest.
The entire formation is in two loops, overlapping and intersecting with each other, and the center of the formation leaves a large number of open spaces, which can be used to place traps, which can either slow down the enemy's excessively fast destruction speed, or exchange virtual and real, so that the enemy cannot see the virtual reality. Similarly, the seven books added a large number of walls on the basis of six books, in addition to increasing the area occupied, the interval between the walls and the walls can also place a large number of traps, so that the enemy is invincible, playing the same delaying effect.
The interior of the formation is arranged with the base camp as the core, supplemented by giant cannons and multi-barrel mortars, while taking into account both individual and group damage. In addition, aerial bomb launchers and anti-aircraft rockets are distributed on both sides of the base camp, taking into account the multi-body and single damage of air defense, and the protection of these buildings can basically protect the safety of the base camp.
A series of defensive buildings built around the central airspace of the formation are the shaking boulders, lava cannons and multi-barrel cannons, the health of the shaking boulders is very strong compared to other defensive buildings, which can withstand a large amount of damage, but there is no way to take long-range attack classes, so it is necessary to assist long-range defense buildings such as arrow towers around the formation to ensure the perfection of the formation defense circle, which can adapt to the attack of enemy troops to the greatest extent and ensure that the enemy's destruction rate is not too high.
The position of this formation piggy bank is very cleverly placed, because in the night world, the piggy bank is not a very important defensive building, but it has health points that other defensive buildings do not have, and the piggy bank is destroyed in the night world and will not be taken away from the resources, the piggy bank can be used as a fairly easy strategic building for defense arrangement, used to protect the more important defense buildings, attracting enemy fire is the most suitable.
The distance between the city wall and the defensive building is a very good choice, the city wall can not only block the enemy's attack for the first time, but also allow the defensive buildings within the city wall to have enough time to output damage, and the reasonable formation must be skillfully used to minimize its own losses.