Board Thread:Questions and Answers/@comment-27917177-20160305012242/@comment-27917177-20160307040556

Cannon7 wrote: I think it is the arena you open it in. Just tried it with a Crown Chest: was in Builder's Workshop for about ten minutes...I'm terrible. But when I opened the chest from the 10 crowns I got in Arena 5 I unlocked the Mortar.

Did you get all 10 crowns in arena 5 and wait? or did you get the last crowns in the game that got you to Arena 6?