The company has posted detailed notes on the fix on its website. The bottom line is that a Legendary Purple Engram will now always yield a valuable Legendary quality item or higher. Previously, players were often disappointed to find engrams converted into useless low-level items, an issue that has produced much criticism and debate about Destiny's overall loot system.
The accidental appearance of loot caves in the game, in which players could easily collect large stashes of loot, became something of an online sensation in the days following the game's release.
Rare (Blue) and Legendary (Purple) Engram drops have also been added to the potential rewards for Vanguard: Tiger Strike Playlist, Daily Heroic Missions (first time per day) and Weekly Heroic Missions (first time per week).