Final Fantasy XIII/Synthesis

Weapons and accessories fall into certain synthesis groups, which, when combined, can create passive abilities for your characters that would otherwise be unavailable. There are 29 synthesis groups, and the more items you equip within that group, the stronger the ability will be.

Adamancy

 * Ability: Vampiric Strike (4–5 equips)
 * Weapons: Aldebarans/Sadalmeliks, Organyx/Apocalypse, Tigerclaw/Wyrmfang
 * Accessories: Cherub's Crown, Seraph's Crown, Zealot's Amulet, Battle Talisman

This ability returns 1% of the damage you deal back to your character as HP. At later stages of the game when you do quite a bit of damage and the fights can be very long, this is a great ability for an offensive character who can regain health while staying in an attacking role. Used with Genji Glove, which removes the cap on damage you inflict, you can see quite a bit of health return to you with this ability.

Boost

 * Ability: ATB Rate: +10%, +15%, 20%, 30%
 * Weapons: Antares Deluxes/Fomalhaut Elites, Axis Blade/Enkindler, Otshirvani/Urubutsin
 * Accessories: Hermes Sandals, Sprint Shoes, Whistlewind Scarf, Aurora Scarf, Nimbletoe Boots

Increases how quickly the ATB Gauge refills, up to 30% faster. This is one of the best passive abilities in the game, and combined with a paradigm that starts a Synergist to Haste you, you'll find you can fit way more attacks between your enemies' attacks.

Curse Resistance

 * Ability: Curse Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Warding Talisman, Hexbane Talisman

Reduces the amount of time the Curse status ailment will affect you, up to four equips.

Damage Reduction

 * Ability: Damage Wall: 5, 10, 15, 20
 * Weapons: Malphas/Naberius, Pleiades Hi-Powers/Hyades Magnums, Sacrificial Circle/Indomitus
 * Accessories: Titanium Bangle, Adamant Bangle

Adds a physical and magical wall to your character, reducing the all damage they take by up to 20, depending on how many items you have equipped. Even with five items giving you 20 damage reduction, this becomes a very small amount later in the game when enemies routinely do damage in the hundreds. This is a good passive ability to use early in the game when your HP is lower, and there are plenty of weapons and accessories that will provide it, but try for a better passive ability once you outgrow this one.

Daze Resistance

 * Ability: Daze Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Rainbow Anklet, Moonbow Anklet

Reduces the amount of time the Daze status ailment will affect you, up to four equips.

Debrave Resistance

 * Ability: Debrave Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Giant's Glove, Warlord's Glove

Reduces the amount of time the Debrave status ailment will affect you, up to four equips.

Defaith Resistance

 * Ability: Defaith Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Glass Buckle, Tektite Buckle

Reduces the amount of time the Defaith status ailment will affect you, up to four equips.

Deprotect Resistance

 * Ability: Deprotect Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Metal Armband, Ceramic Armband

Reduces the amount of time the Deprotect status ailment will affect you, up to four equips.

Deshell Resistance

 * Ability: Deshell Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Serenity Sachet, Safeguard Sachet

Reduces the amount of time the Deshell status ailment will affect you, up to four equips.

Earth Resistance

 * Ability: Earth Damage: +20%, 30%, +50%
 * Weapons: None
 * Accessories: Clay Ring, Siltstone Ring, Gaian Ring, Earth Charm

Boosts your earth damage up to four equips. This will only help party leaders with Quake, as only party leaders ever use techniques. A Saboteur will help if they cast Imperil on the enemy as well.

Fire Resistance

 * Ability: Fire Damage: +20%, +30%, +50%
 * Weapons: None
 * Accessories: Ember Ring, Blaze Ring, Salamandrine Ring, Flamebane Brooch, Flameshield Earring, Fire Charm

Boosts your fire damage up to four equips. You will need a Synergist to imbue weapons with Enfire to boost physical attacks, and a Saboteur will help if they cast Imperil on the enemy as well.

Fog Resistance

 * Ability: Fog Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: White Cape, Effulgent Cape

Reduces the amount of time the Fog status ailment will affect you, up to four equips.

Gestalt

 * Ability: Random: Instant Chain (2–3 equips), Gestalt/TP Boost (4–5 equips)
 * Weapons: Alicanto/Caladrius, Hauteclaire/Durandal, Heavenly Axis/Abraxas, Lionheart/Ultima Weapon, Procyons/Betelgeuse Customs, Rigels/Polaris Specials, Taming Pole/Venus Gospel, Unsetting Sun/Midnight Sun
 * Accessories: Survivalist Catalog, Hunter's Friend, Speed Sash, Energy Sash, Champion's Badge

This ability, granted from equipping two or three items, provides a small chance of immediately filling an enemy's chain gauge.
 * Random&#58; Instant Chain

This ability, granted from equipping four or five items, speeds up the rate at which your TP and Gestalt gauges fill.
 * Gestalt/TP Boost

High HP

 * Ability: High HP: Power Surge
 * Weapons: Healer's Staff/Physician's Staff, Paladin/Winged Saint
 * Accessories: Iron Bangle, Mythril Bangle

Increase your character's damage when their HP is over 90%. Use either a Medic in your paradigm to keep the character's HP up, or a Sentinel so your character doesn't take damage for best results.

Ice Resistance

 * Ability: Ice Damage: +20%, +30%, +50%
 * Weapons: None
 * Accessories: Frost Ring, Ice Ring, Boreal Ring, Frostbane Brooch, Frostshield Earring, Ice Charm

Boosts your ice damage up to four equips. You will need a Synergist to imbue weapons with Enfrost to boost physical attacks, and a Saboteur will help if they cast Imperil on the enemy as well.

Imperil Resistance

 * Ability: Imperil Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Pearl Necklace, Gemstone Necklace

Reduces the amount of time the Imperil status ailment will affect you, up to four equips.

Independent

 * Ability: None
 * Weapons: All final forms
 * Accessories: Various

The Independent synthesis group belongs to no group and has no ability associated with it. All weapons, when transformed to their Omega version, lose any synthesis abilities the previous two incarnations had. This is also the catch-all category for accessories without a synthesis group.

Lightning Resistance

 * Ability: Lightning Damage: +20%, 30%, 50%
 * Weapons: None
 * Accessories: Spark Ring, Fulmen Ring, Raijin Ring, Sparkbane Brooch, Sparkshield Earring, Lightning Charm

Boosts your lightning damage up to four equips. You will need a Synergist to imbue weapons with Enthunder to boost physical attacks, and a Saboteur will help if they cast Imperil on the enemy as well.

Low HP

 * Ability: Low HP: Power Surge
 * Weapons: Airwing/Skycutter, Lifesaber/Peacemaker, Mistilteinn/Erinye's Cane, Rebel Heart/Warrior's Emblem
 * Accessories: Tungsten Bangle

Increase your character's damage when their HP is under 10%. Best used on a character with a lot of HP, so that 10% is a larger actual number. If you plan on actively using this ability, try to put protection on the character (Protect and Shell) once they're under 10% to protect them from dying. Sentinels also work well, as they already have reduced damage while guarding.

Magic Defense

 * Ability: Magical Wall: 5, 10, 20, 30
 * Weapons: Deneb Duellers/Canopus AMPs, Edged Carbine/Razor Carbine, Hawkeye/Eagletalon, Partisan/Rhomphaia, Pearlwing Staff/Brightwing Staff, Punisher/Banescissor Spear, Rod of Thorns/Orochi Rod, Umbra/Solaris, Vega 42s/Altairs
 * Accessories: Gold Bangle, Diamond Bangle, Magician's Mark, Shaman's Mark, Sorcerer's Mark, Weirding Glyph, Rune Bracelet, Witch's Bracelet, Magus's Bracelet, Auric Amulet, Saint's Amulet, Soulfont Talisman, Blessed Talisman

Adds a magical wall to your character, reducing the magical damage they take by up to 30, depending on how many items you have equipped. Even with five items giving you 30 damage reduction, this becomes a very small amount later in the game when enemies routinely do damage in the hundreds. This is a good passive ability to use early in the game when your HP is lower, and there are plenty of weapons and accessories that will provide it, but try for a better passive ability once you outgrow this one.

Pain Resistance

 * Ability: Pain Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Pain Dampener, Pain Deflector

Reduces the amount of time the Pain status ailment will affect you, up to four equips.

Physical Defense

 * Ability: Physical Wall: 5, 10, 20, 30
 * Weapons: Binding Rod/Hunter's Rod, Bladed Lance/Glaive, Blazefire Sabre/Flamberge, Ninurta/Jatayu, Power Circle/Battle Standard, Gladius/Helter-Skelter, Wild Bear/Feral Pride
 * Accessories: Silver Bangle, Platinum Bangle, Power Wristband, Brawler's Wristband, Warrior's Wristband, Power Glove, Black Belt, General's Belt, Champion Belt, Guardian Amulet, Shield Talisman, Hero's Amulet, Morale Talisman

Adds a physical wall to your character, reducing the physical damage they take by up to 30, depending on how many items you have equipped. Even with five items giving you 30 damage reduction, this becomes a very small amount later in the game when enemies routinely do damage in the hundreds. This is a good passive ability to use early in the game when your HP is lower, and there are plenty of weapons and accessories that will provide it, but try for a better passive ability once you outgrow this one.

Poison Resistance

 * Ability: Poison Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Star Pendant, Starfall Pendant

Reduces the amount of time the Poison status ailment will affect you, up to four equips.

Positive Effect

 * Ability: Buff Duration: +30%, +50%, +70%, +90%
 * Weapons: Belladonna Wand/Malboro Wand, Gae Bolg/Gungnir, Pandoran Spear/Calamity Spear, Spica Defenders/Sirius Sidearms, Vidofnir/Hresvelgr
 * Accessories: Watchman's Amulet, Shrouding Talisman

This ability increases the duration of status enhancements applied to the character, up to +90%.

Slow Resistance

 * Ability: Slow Duration: -20%, -40%, -60%
 * Weapons: None
 * Accessories: Glass Orb, Dragonfly Orb

Reduces the amount of time the Slow status ailment will affect you, up to four equips.

Ultimate Magic

 * Ability: Magic Damper (five equips only)
 * Weapons: Feymark/Soul Blazer, Shamanic Spear/Heretic's Halberd
 * Accessories: Magistral Crest×4

This ability grants you immunity to all magical damage, however you must have five items in this synthesis group equipped, and the only weapons with this group belong to Snow and Fang. Attaining this ability also renders you incapable of being restored by magic, so you will be limited to items and Eidolons if you need to heal, be raised or have status ailments removed. Obviously this ability is best against very strong enemies who only perform magical attacks.

Ultimate Physic

 * Ability: Ethereal Mantle (five equips only)
 * Weapons: Dragoon Lance/Dragonhorn, Simurgh/Tezcatlipoca
 * Accessories: Kaiser Knuckles ×4

This ability grants you immunity to all physical damage, however you must have five items in this synthesis group equipped, and the only weapons with this group belong to Hope and Fang. Attaining this ability also renders you incapable of being restored by magic, so you will be limited to items and Eidolons if you need to heal, be raised or have status ailments removed. Obviously this ability is best against very strong enemies who only perform physical attacks.

Water Resistance

 * Ability: Water Damage: +20%, 30%, 50%
 * Weapons: None
 * Accessories: Aqua Ring, Riptide Ring, Nereid Ring, Aquabane Brooch, Aquashield Earring, Water Charm

Boosts your water damage up to four equips. You will need a Synergist to imbue weapons with Enwater to boost physical attacks, and a Saboteur will help if they cast Imperil on the enemy as well.

Wind Resistance

 * Ability: Wind Damage: +20%, 30%, 50%
 * Weapons: None
 * Accessories: Zephyr Ring, Gale Ring, Sylphid Ring, Wind Charm

Boosts your wind damage up to four equips. This will only help Ravagers, as they are the only role with Aero abilities. A Saboteur will help if they cast Imperil on the enemy as well.