Talk:Akashi's Improvement Arsenal/@comment-24375640-20151016064442/@comment-26410405-20151017200011

Typically after you've upgraded to +6 the difficulty increases. I only ever had 1 failure when improving from +1 to +6, every other time it was always success. Yet when improving from +6 to +10 I've had 3-4 failures, one of them even from +6 to +7. It's up to you if you want to risk it, but sometimes it's not worth to fail, especially if rare equipment is involved.