Crystal Synthesis

Crystal Synthesis, colloquial crafting, is a the system used in Final Fantasy XI where a player uses a crystal plus other materials to create another object. Crystals can be, but are not always, obtained in the game when a creature is defeated by a player. Only creatures that will grant the player experience can drop crystals. These crystals, one for each of the eight elements, can be used opening an item synthesis menu. There are recipes for hundreds of items that can be made.

Example
Each crystal represents a different type of action. In the case of fire crystals, this represent adding heat. When the player adds heat to distilled water and animal bones they can create gelatin.

Types of Crafting
Each recipe of synthesis falls under a crafting category. Some recipes have a subtype, which basically dictate the high quality synthesis rate.

Each recipe has a difficulty. If the player's skill is below the crafting level for the recipe, they have a greater chance of failing his synthesis attempt. If the player fails, they will lose the crystal and possibly some or all of the materials used in the synth, for short.

High Quality
If the player has more skill than is required to make the item, they have a greater chance of making a High Quality item, an improved version of the original. In the case of potions or other medicine, this means it will restore more HP, MP, and/or whatever other effect it has. In the cases of armor, it usually grants better Defense bonus. In the case of weapons it usually makes the weapon slightly faster or increases its damage. Special effects and ability modifiers are also greater on High Quality materials.