Barrier materia is a 
Magic Materia in Final Fantasy VII Rebirth. It provides spells that halve damage of a certain damage type. These spells are 
Barrier, which halves physical damage; Manaward, which halves magic damage; and Manawall, which halves both.
Though Fortification Materia exists and also provides spells that improve resistance, they provide boosts to a party member's defense, as opposed to halving a damage type.
Obtained[]
The barrier materia is sold for 1500 gil apiece in shops that sell materia from chapter 6, "Fool's Paradise". onward.
A level 2 barrier materia is won from "Cosmo Canyon Region Intel: Level 1" in Chadley's combat simulator.
Barrier materia in Shinra Manor.
A level 2 barrier materia is also found in the Shinra Manor basement when in control of Cait Sith in chapter 11, "The Long Shadow of Shinra". It is found on the Section N just right after the corridor with numerous breakable boxes.
Stats[]
Growth[]
| Level | AP required | Effect |
|---|---|---|
| 1 | 0 | Barrier |
| 2 | 300 | Manaward |
| 3 | 900 | Manawall |
Abilities[]
| Magic | MP | Effect |
|---|---|---|
| Barrier | 11 | Applies the  Barrier effect, granting 50% resistance to physical damage.
|
| Manaward | 14 | Applies the  Manaward effect, granting 50% resistance to magical damage.
|
| Manawall | 20 | Applies the both the Barrier and Manaward effect, providing 50% resistance to all damage. |
Use[]
The barrier materia grants spells that apply damage-mitigating effects. Barrier provides the Barrier effect, which halves physical damage received. Manaward applies the Manaward effect, which halves both. Manawall grants both effects at once. Depending on the damage used by the enemy type, barrier materia spells can provide great durability in battles and can be important to resist powerful attacks.
Though the fortification materia grants the spells Protect and Shell, which grant 
Protect and 
Shell, these boost a party member's defensive attributes rather than outright slashing the incoming damage in half. They can be additive to the protection provided by barrier materia spells to improve one's defense further. They also oppose the negative effects, namely 
Deprotect and 
Deshell. As such, fortification serves a similar yet distinct purpose to barrier materia. Overall, however, the spells from barrier materia, while costlier, are more impactful, and if a player must choose, barrier spells are usually a better option.
Barrier materia can be combined very effectively with 
Magnify Materia to grant the effects to all party members at once. In many fights this can be extremely important to resist certain attacks, making this a common pairing. Magic Focus Materia can increase the effects' lengths, while Magic Efficiency Materia can reduce their great MP costs.
The barrier materia also provides many attribute bonuses that help spellcasters. Otherwise, its spells are unaffected by the attributes of the caster, and thus the materia can be given to any party member with MP to spare. Barret can benefit greatly in particular due to his Lifesaver ability, which causes him to take damage intended for other party members; protecting the other party members will cause the damage coming to him to also be reduced.