The Forbidden Land, Eureka Gear Guide
The level 70 field operation series 
The Forbidden Land, Eureka has its own gear progression relying on Elemental Bonus that can greatly enhance player power within the zones. This guide provides an overview of entry-level to best-in-slot gear for Eureka. [1]
Starting gear
- In general, use the highest item level (IL) gear you have, which will sync down to IL 300. Gear above IL 450 (i.e., most level 80+ gear) have maximal substats when synced down.
- Players on the Free Trial can use Augmented Scaevan Weapons, Augmented Scaevan Armor, and Augmented Scaevan Accessories (IL 400) purchased with
Allagan Tomestones of Poetics. - If possible, purchase one of the following chest armor from the Market Board, depending on your job. This chest armor is best-in-slot for Eureka and cannot be further upgraded.
- Depending on your data center/world, it may be cheaper to purchase the requisite materials for these items, which can be traded for the armor from the Nostalgic Fellow in Kugane (7.8, 14.2).
- Disciple of War armor (Kirin's Osode): 2
Cryptic Seal (price tracker) - Disciple of Magic armor (Vermilion Cloak): 3
Damascene Cloth (price tracker)
- Disciple of War armor (Kirin's Osode): 2
- Disciple of Magic Vermilion Cloaks cover both the chest and head slots, so it is not possible to have any head glamour if equipped.
Best-in-slot gear
Best-in-slot weapons and armor are obtained in Eureka at the end of lengthy upgrade processes, culminating with completing The Baldesion Arsenal multiple times. Only the final-stage weapons and armor have Elemental Bonus and are best-in-slot. Intermediate stage Eureka gear is worse than starting, item level synced gear due to having fewer substats and no Elemental Bonus. Therefore, only replace a starting gear piece once you have acquired the best-in-slot piece.
Weapons
IL 405 Physeos Weapons are the 16th and final stages for Eurekan Weapons and are best-in-slot weapons for Eureka. See the preceding links for more information on acquisition.
Secondary stats for these weapons can be rolled on in the Mnemeworks Station in Eureka Pyros. For more information, see here. It is not necessary to attempt to optimize for a perfect (or even decent) roll, which can be very time-consuming, as the secondary stats provide only a marginal increase in damage compared to the Elemental Bonus from the weapon.
Jobs added after Stormblood: 
gunbreaker, 
dancer, 
sage, and 
reaper do not have Physeos Weapons (or any Eureka weapon), making them somewhat weaker than jobs that do.
Armor
IL 390 Elemental Armor +2 are the third and final stages for Elemental Armor and are generally the best-in-slot armor for Eureka, with some caveats. See the preceding links for more information on acquisition.
- The Elemental +2 chest armor is not best-in-slot in Eureka. Kirin's Osode Armor / Vermillion Cloaks are stronger than the Elemental Armor +2 chest armor in Eureka due to the extra Haste bonus and materia melds being active, while having an identical Elemental Bonus.
- The Elemental +2 head, hands, legs, and feet armor are best-in-slot for Disciples of War in Eureka. The hands, legs, and feet armor are best-in-slot for Disciples of Magic because their Vermillion Cloak chest armor occupies both the head and chest slots.
Accessories
There are no best-in-slot accessories specific Eureka that can be practically obtained, although there are two rare accessories. The easiest option is to use IL 450+ (
high quality if applicable) accessories, as the item level sync will reach the substat cap of 55. In general, prioritize accessories with desirable substats, such as critical hit, determination, and direct hit rate.
Upgrade paths
Depending on the job, accruing enough 
Eureka Fragments requires 7 to 8 runs of the Baldesion Arsenal, assuming they are all full clears, to obtain a Physeos Weapon and all best-in-slot Elemental Armor +2 pieces. The gear with the lowest Elemental Bonuses: one of the feet, hands, and head armor are the most efficient to upgrade first, followed by the legs, then the remaining feet/hands/head, and finally the weapon. This is due to the former gear having a higher "elemental bonus per fragment cost" efficiency than the more expensive legs and weapon.[2]
Materia
Due to item level syncing, materia melds are only active for Kirin's Osode Armor / Vermilion Cloaks, which matches the IL sync of Eureka (300). This chest armor has five materia slots, which should be melded with Grade VI materia, prioritizing critical hit > direct hit rate or determination. Melding other pieces of gear is unnecessary as the melds are wasted.
Vanity items
These items are very difficult or expensive to obtain because they rely on rare random drops. Instead of providing Elemental Bonus, they each provide 3 Haste, decreasing the player's global cooldown (GCD) and auto-attack delay by 3% each. This has a marginal impact on damage compared to Elemental Bonus.
- The
Optical Hat, which is obtained by using a 
Hakutaku Eye Cluster during 
The Wobbler in Darkness, is not best-in-slot under any circumstances because it is outclassed by the Elemental Bonus provided by Elemental Armor +2 or Vermilion Cloaks. - The
Cassie Earring and 
Blitzring, which are obtained as very rare drops from Cassie and the Copycats and Morte Arthro, respectively, could potentially replace an item level synced earring and ring due to their Haste bonus. However, this is at the cost of 9 vitality from a synced earring and 220 substats from both slots. These only provide very minor benefits to certain builds of certain jobs and are therefore not universally considered best-in-slot for Eureka.
References
- ↑ Traffica Falena's BA BIS guide, Aether Bozja & Baldesion Arsenal Discord
- ↑ https://i.imgur.com/1Z7d5ft.png (Recommended Elemental Gear upgrade order)
Source: Aether Bozja & Baldesion Arsenal Discord
