The blue circle is one of the core features of the game and it limits the space in the game for players.
Before the blue circle closes, it is a 'blue zone' and in that zone, the safe area is displayed as a white circle.
After the system displays the message that the blue circle will close, it will close as small as the size of the white circle.
Furthermore, all the players outside of the blue zone will receive damage.
The damage will increase as the additional blue circle develop.
The damage of the blue circle increases in the following order:
First blue circle < second blue circle < Third blue circle