# The difficulty system will be present for this event; you can choose between Operation A (甲, Hard), Operation B (乙, Medium) or Operation C (丙, Easy).
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# The difficulty system first used in [[Spring 2015 Event]] returns: you can choose between Operation A (甲, Hard), Operation B (乙, Medium) or Operation C (丙, Easy).
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# A new system will be introduced at the release of the event that will be equipment related.
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#* Choosing A or B requires certain HQ Level (HQ Lv 35 for B / 80 for A in Spring 2015 Event).
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#* With the exception of E-1, in order to choose Operation A, the previous map must be cleared on A or B.
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# A new system will be introduced with the release of this event involving carrier-based planes.