The flying dragon game played by Vikings in Dragons: Race to the Edge is called dragon racing.
Dragon racing is a competitive activity in which riders use their dragons to navigate courses and compete for victory. It expands the sports and games shown in the How to Train Your Dragon universe beyond ordinary village training.
The series uses dragon racing to showcase the different abilities of its characters and dragons. Speed, maneuverability, teamwork, and knowledge of the environment can all affect the result, making the activity more than a simple contest of strength.
This should not be confused with the dragon-riding game shown in How to Train Your Dragon 2, where the Vikings play a form of dragon racing in the film’s opening sequence. The television series develops the idea across its own episodes and adventures.