The Cape can be obtained by purchasing an Achievement Diary Hood from RuneScape gold Twiggy O'Korn located in Draynor Village located south of the bank. The vendor sells it at 99k GP only to those who have all Diaries completed. Without certainty, one of the most difficult items to acquire in the game , as it is not just a matter of high skill levels and also the successful completion of various tasks which often require a lot of effort.
Achievement Diary Cape is cut following the completion of all quests, which makes the version that is trimmed even more difficult to acquire. Much like Quest Point Cape, this item is cut off as a new quest is brought out. It will only be cut off when all quests in the game are complete. This means that every new assignment must be completed in order to be successful, as well.
The untrimmed and trimmed versions of this cape come with an additional 9 points to all defensive stats and +4 bonus to Prayer skills, which makes it best in slot untrimmed capes to use for Prayer. Achievement Diary Cape also has the ability to teleport daily to anyone who is an Achievement Diary Master, which makes it a perfect transport item.
Although some of the achievements are located in Draynor Village, Varrock, Lumbridge as well as other free to play areas, Achievement Diaries are not accessible to buy RS gold non-member players. This means that even taking the correct action won't give the appropriate rewards to the player who is f2p. Although there have been many rumors about making some new Diaries just for free players, there is no proof from Jagex.