Synthesis is a gameplay mechanic that involves using synthesis materials to craft various items in Kingdom Hearts and its Final Mix version. The option to synthesize items is unlocked after using Trinity Ladder on a green Trinity Mark inside Cid's Accessory Shop to unlock the Item Workshop. Trinity Ladder itself is acquired after completing Agrabah. The Item Workshop is home to Moogles, which require specific materials before the player is able to synthesize the desired items, otherwise synthesizing is entirely free. It is also repeatable except for the Ultima Weapon Keyblade.
Although the synthesis menu displays all items in a single list, they are part of separate sets. Synthesizing enough different items from the first list unlocks the second one, and synthesizing ten different items from both of these unlocks the third, and so on. Later lists have more powerful items that require more and rarer materials. The original game has a total of 25 items available for synthesis, whereas Final Mix has 33, as well as one extra list of a higher tier. Final Mix also rearranged most items, making them cheaper or more expensive (notably Elixir went from list I to V), as well as changing some of the required materials. Notable additions from Final Mix were the Fantasista and Seven Elements, for Donald and Goofy, respectively.
|List I||Cottage, Elixir, Energy Bangle, Power Chain, Guard Earring, Dark Ring||None.|
|List II||Mega-Potion, AP Up, Angel Bangle, Magic Armlet, Golem Chain, Master Earring||Synthesize 4 unique items.|
|List III||Mega-Ether, Defense Up, Gaia Bangle, Rune Armlet, Heartguard, Three Stars||Synthesize 10 unique items.|
|List IV||Megalixir, Power Up, Titan Chain, Atlas Armlet, Crystal Crown, Ribbon||Synthesize 15 unique items.|
|List V||Ultima Weapon||Synthesize all 24 unique items.|
|List I||Mega-Potion, Cottage, Energy Bangle, Power Chain, Magic Armlet, EXP Earring||None.|
|List II||Mega-Ether, Guard Earring, Angel Bangle, Golem Chain, Rune Armlet, Moogle Badge||Synthesize 3 unique items.|
|List III||AP Up, Dark Ring, Master Earring, Gaia Bangle, Titan Chain, Mythril||Synthesize 9 unique items.|
|List IV||Elixir, Defense Up, Heartguard, Three Stars, Atlas Armlet, Crystal Crown||Synthesize 15 unique items.|
|List V||Megalixir, Power Up, Cosmic Arts, EXP Bracelet, Ribbon, Dark Matter||Synthesize 21 unique items.|
|List VI||Fantasista, Seven Elements, Ultima Weapon||Synthesize all 30 unique items.|
Synthesis materials are most commonly acquired by killing Heartless, with item drop rates in Kingdom Hearts generally ranging from twelve to only one percent. Abilities like Lucky Strike enhance this number, but acquiring enough materials always comes down to grinding enough enemies. Some Heartless have extra drop rates under specific circumstances, such as the Powerwild, Bouncywild (both drop items if they slip on a banana peel), and Battleship (drops items if its individual parts are destroyed). The same goes for the mushroom enemies like White Mushroom (drops items dependent on the number and type of magic used), Rare Truffle (requires to be juggled), and Black Fungus (needs to be finished with a critical hit or finisher).
The Final Mix version of Kingdom Hearts drastically lowered almost all drop rates by half or more, and introduced several new materials and enemies, generally one per world. Most of these new enemies also have unique requirements and parameters before they will drop their personal item.
Bambi is also a notable source for material drops, but only if you manage to raise his gauge to full three times in one fight. The actual rewards he grants depend on the world he is summoned in.
The items Mythril, Orichalcum, and Dark Matter (new in Final Mix) are the only items not easily available through killing enemies. Although Mythril and Dark Matter can be synthesized, and Orichalcum purchased at the Item Shop, it is expensive to do so. There are however enough of them available to synthesize every item at least once, by finding them inside treasure chests, completing optional content such as Jungle Slider and Olympus Coliseum cups, finding Trinity Marks, returning the 99 puppies, delivering postcards, and giving Rare Nuts to Owl.
Items below are sorted by type, ranging from the most common to the most rare. The listed enemies are also sorted from most common to most rare. Typically speaking drop rates are higher for more common items, and lower for more common enemies. The aforementioned Final Mix enemies often have 100% drop rates but only if the exact requirements are fulfilled. If you intend to farm specific materials it should be kept in mind on whether to attempt this prior or after the events in Hollow Bastion, as these drastically change the Heartless' strength and appearance rates throughout all worlds.
|Lucid Shard||A gem shard containing essence of emptiness.||Shadow, White Mushroom (Gravity), Gigas Shadow|
|Lucid Gem||A gem containing essence of emptiness.||Gargoyle, Wight Knight, White Mushroom (Gravity)|
|Lucid Crystal||Crystallized essence of emptiness.||Darkball|
|Spirit Shard||A gem shard containing essence of fighting spirit.||Soldier, Large Body, White Mushroom (Aero)|
|Spirit Gem||A gem containing essence of fighting spirit.||Air Soldier, White Mushroom (Aero)|
|Fury Stone (FM)||A mysterious stone filled with fury.||Gigas Shadow|
|Power Shard||A gem shard containing essence of strength.||Powerwild, Bouncywild, White Mushroom (Stop)|
|Power Gem||A gem containing essence of strength.||Pirate, Air Pirate, Battleship, White Mushroom (Stop)|
|Power Stone (FM)||A mysterious stone filled with power.||Sniperwild|
|Power Crystal[a]||Crystallized essence of spirit and strength.||Wyvern|
|Energy Stone (FM)||A mysterious stone filled with energy.||Stealth Soldier|
|Bright Shard||A gem shard containing essence of vitality.||Green Requiem, White Mushroom (Cure)|
|Bright Gem||A gem containing essence of vitality.||Search Ghost, White Mushroom (Cure)|
|Bright Crystal||Crystalized essence of vitality.||Defender|
|Blaze Shard||A gem shard containing essence of fire.||Red Nocturne, White Mushroom (Fire)|
|Blaze Gem||A gem containing essence of fire.||Bandit, Fat Bandit, White Mushroom (Fire)|
|Blazing Stone (FM)||A mysterious stone filled with fire.||Chimera|
|Frost Shard||A gem shard containing essence of ice.||Blue Rhapsody, White Mushroom (Blizzard)|
|Frost Gem||A gem containing essence of ice.||Sea Neon, Sheltering Zone, White Mushroom (Blizzard)|
|Frost Stone (FM)||A mysterious stone filled with ice.||Grand Ghost|
|Thunder Shard||A gem shard containing essence of thunder.||Yellow Opera, White Mushroom (Thunder)|
|Thunder Gem||A gem containing essence of thunder.||Screwdiver, Aquatank, White Mushroom (Thunder)|
|Lightning Stone (FM)||A mysterious stone filled with lightning.||Black Ballade|
|Shiny Crystal||A crystal bursting with the essence of three elements.||Wizard|
|Dazzling Stone (FM)||A mysterious stone filled with light.||Jet Balloon|
|Mythril Shard||A mineral shard containing rare metal.||Kingdom Hearts: Behemoth |
Final Mix: Arch Behemoth
Both: Barrel Spider, Pot Spider, Bambi, chests
|Mythril||An extremely rare metal ore.||Kingdom Hearts: Angel Star, Behemoth |
Final Mix: Item synthesis (list III)
|Mythril Stone (FM)||A mysterious stone born from a rare ore.||Pot Scorpion|
|Mystery Goo||Droplet of a crystalized, mysterious substance.||Rare Truffle, White Mushroom, Black Fungus|
|Serenity Power (FM)||A mysterious crystal filled with feelings of gratification.||Pink Agaricus|
|Gale||A howling gale frozen in crystal form.||Angel Star, Invisible|
|Stormy Stone (FM)||A mysterious stone filled with wind.||Neoshadow|
|Orichalcum||A rare and most valuable ore.||Kingdom Hearts: Invisible, Behemoth |
Final Mix: Can be purchased from the Item Shop for 5,000 munny.
Both: Must be found throughout the game worlds.
|Dark Matter (FM)||A rare ore found once in a blue moon.||Must be found throughout the game worlds. Item synthesis (list V).|
- This is actually a mistranslation of 'Energy Crystal'
- End of the World is the only location where Bambi can drop Mythril, and only in the area called 'Linked Worlds' where you must fight a large amount of enemies. Summon Bambi after the Behemoth, then retreat when his gauge is filled three times. Finishing the fight entirely and entering Final Rest will cause Neoshadows to spawn here instead.