Board Thread:Dragon City Gameplay Questions & Answers/@comment-10859005-20130621150745/@comment-10090661-20130622005719

Reply #2: The % refers to improvement of the attack if replaced with the new one. (I think there was a bug with the code, it may have been fixed by now, but ignore the graphics anyway.) The % shown is a "sample" of the improvement in damage compared to a "sample" of the damage with the old attack. It's basically useless, so I would ignore it. :)