- Estimated Achievement Difficulty: 5-7/10 [not hard, but ridiculously time consuming!!]
- Offline: 0 
- Online: 57 
- Approximate amount of time to 1250: 6 months - 2+ years
- Minimum number of playthroughs needed: 1
- Number of missable achievements: 0
- Do cheat codes disable achievements: No cheats
- Does difficulty affect achievements: No
- Glitchy achievements: None
- Unobtainable achievements: None
- Extra equipment needed: Subscription Fee, Keyboard would make things easier
Welcome to the Final Fantasy XI roadmap to 1250 . The game isn't necessarily hard, but is extremely time consuming and heavily relies on having friends join you to accomplish quite a bit of the achievements on this list. The game does require its own subscription fee, though it does not require Xbox Live Gold in order to connect online.
I mention getting a keyboard for the 360, mainly for one reason; the chat pad does indeed work, but it is weird. To use any capital letters, shift will not work. You will need to set Caps Lock in order to input any capital letters. Also, in order to make any of the green light symbols, you will need to hit the method twice - the green light toggles the User Interface in the game, so hitting it the first time takes the UI away. Hit the symbol you want anyway (it won't input) so that you can hit the green light again for the UI to come back and the green light lit up to actually input that symbol. To me, these two things about the chat pad are just annoying enough to warrant an actual keyboard. Both are 'extra equipment' that are not necessary to play the game, but you won't get too far into the group-based events without some kind of communication method.
Having said that, the game can be a lot of fun if you have a lot of patience and perseverance. There are plenty of things to do outside of the achievements, so much that it can seem a bit overwhelming trying to take it in all at once. Since its release, the game has seen quite a bit of updates and enhancements, keeping the gameplay fresh and exciting for even the FFXI veteran.
On to why you're here: Achievements! Every achievement is listed as secret. None of them are spoilers, so you can rest assured looking at them won't spoil anything for you. Achievements don't unlock as you play like an achievement would normally in any other game. Instead, once you have met the requirements for the achievement, you must talk to an NPC dressed as a Bard who can change your character's title. On the Xbox 360 version of the game only, there will be an extra option to unlock any achievements you have pending to unlock. Since the game saves your character data to the server, and is multi-regional and multi-platform, this opens up a variety of platforms you're able to play on without hindering your achievement progress.
For instance, you could attain level 75 Warrior on the PC, then complete the Windurst rank missions on the PS2, then jump on 360 and unlock the achievements for both. You can unlock any achievement you like at any time while on the 360, no matter which platform you achieved the requirement on.
For reference to everything you could ever ask about the game, consult some of the unofficial (most popular) wiki sites:
Gamer Escape Final Fantasy XI
Step 1: Job Levels.
There are 20 jobs to level to 75 for a total of 600 . As the achievements suggest, simply get Level 75 with each corresponding job. There are some hurdles along the way in the form of level caps and quests to unlock them - which start at level 50 and continue to block your path every 5 levels from there. Luckily, you only need to do a level cap quest once on any job to raise the level cap for all jobs. With the help of your friends, you can form a party to earn experience points. Alternatively, you can go it alone with various solo-helpful aspects of the game like Fields of Valor. Two more jobs are included with the Seekers of Adoulin expansion (Rune Fencer and Geomancer), but there are no achievements related to them.
Step 2: Story.
There are 9 story-related achievements for a total of 300 . The main game gets three for its national ranks, then each expansion gets its own achievement.
There are two extra achievements for doing unnecessary portions of optional story. This includes "Breaker of the Chains" (20 ), and "Past Vana'diel Nation Quests" (20 ). The Seekers of Adoulin expansion is excluded from this list.
Step 3: Solo-ish Achievements
There are 22 achievements for a total of 180 that you can obtain on your own without necessarily requiring the help of your comrades. This includes all of the 5 achievements, in addition to "Medal of Altana" (30 ), and "Synthesis Skill" 100 (50 ). These are all fairly straight-forward and easy to get.
The real trouble is getting the achievements for your level cap quests for job levels 50 and 55: "Horizon Breaker" (5 ) and "Summit Breaker" (5 ). Since you can only complete the quest once, and you cannot attain a higher level until you do, you will be stuck fighting monsters that are tougher than you for both of these quests.
Step 4: Group Events
Finally, there are 6 achievements for a total of 170 that require you to have a group to complete, as the difficulty of the monsters is too great even for Lv99. Hopefully by the time you hit Lv75 you've found yourself a nice array of friends and a linkshell to call home to get some of these rewarding raid-like instances complete.
Final Fantasy XI is a challenging yet highly rewarding game in both game content and story. The achievements are nothing too strenuous, but definitely take a lot of time and effort to go for 100%. There is a lot to take in and consider when shooting for any one achievement, enough to feel overwhelmed when looking at the big 100% picture. Keep in mind that Abyssea, Voidwatch, Legion, and the entire expansion of Seekers of Adoulin are not a part of this achievement list, as well as many other aspects of the game not listed here.
I would not recommend this game just for the achievements, but rather use the achievements as a good checklist of things to do while you enjoy playing the game.
[x360a would like to thank theheroslegend for this Road Map]