Those looking for Final Fantasy XIV's Astrologian job unlock only need to have access to FFXIV's Heavensward expansion in terms of content, but they'll need to complete a particular Main Scenario Quest (MSQ) in addition to two other miscellaneous job requirements. Because all past expansions for FFXIV are included if the latest expansion is purchased (Endwalker is the latest at time of writing), and because the current Standard Edition of the game includes Heavensward's content, anyone currently playing the game should have everything they need to get the Astrologian job in FFXIV unlocked - at least once they've advanced far enough in the game.
Among the diverse roles in Final Fantasy XIV, Healers (like Astrologians and White Mages) are always in high demand, and a necessity for any team taking on Trials or Dungeons. However, the card-wielding Astrologian is itself unique among the spectrum of support jobs in Final Fantasy XIV in that it's not immediately accessible and requires players to jump through some hoops before they can finally access it.
To get the Astrologian in Final Fantasy XIV unlocked, players need to finish the entire A Realm Reborn campaign. All the MSQ until Heavensward should be completed, up to and including the "Before the Dawn" quest. Additionally, players will need to have reached Level 50 or higher in a Disciples of War or Magic job. After these prerequisites have been met, players will need to enter Ishgard, a city in Coerthas, that becomes available as Heavensward's story begins. They will need to then accept the quest "Stairway to the Heavens" from Jannequinard, granting access to the Astrologian storyline - but not until that quest is also completed. Until then, players won't be able to unlock the Astrologian job in FFXIV or its equipment.
How To Unlock The Astrologian In FFXIV
There are two ways to quickly complete all the base game's MSQ and reach Level 50. First, players can play FFXIV with a sharp focus on finishing the main story. Generally, this is the proper method to engage with the story and its colorful cast of characters in the first place, and it will act as the proving grounds for learning the basics of a class or job through efficient leveling in Final Fantasy XIV. However, those in a hurry to unlock FFXIV's Astrologian job might consider the second option a better choice: purchasing a progression boost that skips A Realm Reborn entirely. It's an affordable alternative, especially for players who don't wish to spend 30+ hours on the main story, though may rush newer players past a lot of valuable content in terms of both story and mechanical nuances.
Once players wanting to unlock the Astrologian in FFXIV have made it to Ishgard, they can enter a zone known as The Pillars, where they can find Jannequinard waiting for them. If in doubt about his location, he will show up at map coordinates X: 15.2, Y: 10.0. From there, all that needs to be done is completing the "Stairway to the Heavens" quest, and FFXIV's Astrologian job will be unlocked at last.