Board Thread:Wiki discussions and announcements/@comment-26053782-20150129202217/@comment-26053782-20150630191145

On patch 5.8 it also said:

"This is a little complicated, but the short of it is that the Dragon's Might buff was calculating its +6% AD a little weird. First, it didn't multiply with bonus attack damage (so that's no good) and second, it assumed a 1.0 AD ratio for anything that used an AD ratio (even if that ratio was, in reality, much lower). This isn't to say that AD scaling spells were all using 1.0 ratios, just that the +6% AD on Dragon's Might was scaling like that. This also probably exposes a bit of how math works in our game, but that's a confusing bag of goodies in and of itself.

Auto attack damage for champions with Dragon's Might and AD items will now be slightly higher

Physical damage spells will now deal slightly less damage when interacting with Dragon's Might (unless the champion has a lot of bonus AD or their abilities scale higher than 1.0 AD)"