BD BS Abilink is a feature in Bravely Default and Bravely Second: End Layer, in which one of the player characters links up with a friend, allowing the character to "borrow" the job levels of their friend.
Abilink grants the player the ability to make use of job abilities even if the character has no experience in that job. However, they are limited to the abilities that their friend has learned. Job levels and abilities gained by this method are highlighted in orange.
In order to use Abilink, the player must first register another player as a friend on their Nintendo 3DS. The two can then connect either through street pass or through the internet by talking to the Adventurer. The friends can update their information through the Update Data option. The game also provides four computer players; Friend-bot, Buddy-Bot, Pal-Bot, and Amigo-Bot. These bots will gain levels over time, but are much more limited than real players.
Abilinking itself is done by going into the menu and selecting Tactics. A submenu will be pulled up and Abilink will be available as an option. The player can then select one of the characters, and choose a friend to link with. Each character can only Abilink with one other player at a time.