Defensive Buildings are buildings mainly built to defend your castle while you are offline. Of course, your defensive buildings cannot guarantee your castle remains safe. A Shield is the only item that can do that.
Towers are Buildings that attack enemy intruders. The Watchtower is the basic tower, which can be upgraded into Arrow Tower, Magic Tower or Cannon Tower. These upgraded Towers also gain a new feature called Garrison.
|Watchtower||Arrow Tower||Magic Tower||Cannon Tower||Garrison|
Traps can be placed on the ground and explode after enemy ground units come in range. After exploding you need to replace the traps with new ones. The Hero Trap attacks Heroes only and the Bomb Trap responds to troops only.
|Hero Trap||Bomb Trap|
Your first line of defense. Place them strategically to hinder the enemy's ground troops advance.