I know blue engrams are supposed to still have a chance to give legendary rewards. But even after turning in countless blue engrams, I can count the number of times I've gotten a legendary on one hand after cutting all my fingers off.
English
#Destiny
-
It's very very rare. I saved up all my blues from my main and first alt, so when my second alt hit 20 I could turn them all in for blue gear with light. I got plenty of blue gear but not a single purple. Days later - 1 purple chest from a blue... I think it was because I was already wearing an exotic chest and the Cryptard hadn't given me the finger in awhile.