Talk:Summer 2015 Event/@comment-26900408-20150817182254/@comment-25730832-20150817183936

It's your HQ Level.

Read here: 
 * This event has three (3) difficulty selections or otherwise known as ranks:
 * easy (丙) (Available from Headquarter level (HQ level) 1 and spans up to level 35)
 * medium (乙) (Unlocks at Headquarter level (HQ level) 35 and spans up to level 80)
 * hard (甲) (Unlocks at Headquarter level (HQ level) 80 or above)

Your default is "Easy". Just do Easy. Believe me...you ain't going far with medium or above.