To celebrate Fire Emblem Heroes Nintendo announced the 1.5x EXP Event, which runs from now until February 22nd, 2017 at 10:59 PM PT. This is a great way to earn extra experience for your heroes and heroines in Fire Emblem Heroes. This EXP can be earned using the Story Maps, Training Tower, Special Maps or the Arena. Fire Emblem Heroes released on February 2nd, and is the 3rd major mobile game published by Nintendo after Super Mario Run and Pokemon GO.
— Nintendo of America (@NintendoAmerica) February 17, 2017