We present a complete design and implementation of a system that consists of multiple quadrotors playing capture the flag game. Our main contributions in this work include a custom built quadrotor platform, an efficient implementation of a distributed trajectory planning algorithm, and a WiFi based communication infrastructure. In our design, we equip the quadrotors with autopilot modules for low level control. Moreover, we install low power computing modules for implementing the distributed trajectory planning algorithm online. Furthermore, we develop a communication infrastructure to enable coordination among the quadrotors, which is required for computing a suboptimal control action in real time. The interactions among all the hardware and software components are managed at a higher level by Robot Operating System (ROS). To test the performance of the system, we select a motivating setup of capture the flag game, which is an adversarial game played between two teams of agents called attack and defense. The system is initially simulated in the Gazebo robot simulator with software in the loop. Finally, the complete system is tested and the flight testing results are presented.