I just learned from looking at the official Diablo 3 site that there are a variety of Blacksmith Plans that you have to require in order to craft certain rare and legendary items. I have not seen any of these drop so far in my game, nor have I seen them for purchase at the Blacksmith or other vendors.
Does anyone know how you get access to these plans?
Best Answer
According to Blizzard, there are 3 Normal, 87 Rare, and 39 Legendary Blacksmith Plans. We know that the three normal ones are dropped by Izual in Act 4 on the respective difficulty levels.
Anecdotally by forum posts, it looks like people are finding one or two per difficulty (bnet forum post) from random monster/champion/boss drops, although one person notes none found on his way to Inferno. So far the only non-Blizzard list this gamer found was at d3db, and it just lists "Drop" as the source of each of the plans.