The Basics
The following is just a BASIC understanding of how Dualizing Weapons and Armor works to create gems.
If you want more detail, you should visit the great guide on it here: http://www.gamefaqs.com/ps3/604158-tales-of-graces-f/faqs/64159 I don't see a point in writing information that someone has already done better.
Qualities
The quality should more accurately be called ranks. This is what makes your weapon and armor more powerful. Each equipment and shard has it's own quality that has different effects when combined together. Sometimes the quality simply boosts the equipmnent normally, but sometimes you will get unexpected results. All qualities have a "rank" that determines what it does when dualized with another quality. See the following page on Qualities for more information.
Dualizing Qualities
As stated, each equipment has it's own quality, but in order to increase it you need to take the following into account:
- If you dualize an equipment and shard of different quality, the new equipment will take on the lower-ranking quality.
- Example: Cool + Olden = Cool (because it is the lesser ranked quality)
- If you dualize an equipment and shard of the same rank, the new equipment will have a different quality.
- Example: Keen + Cool = Noble or Keen + Hard = Tolerable
- There is also the cameo qualities that can only be unlocked through the Grade Shop's > Unlock Qualities purchase:
- Example: Cool + Noble = Guyabulous"
Once in a while there is a special effect, marked in orange, that can occur. This is an added bonus for this quality on this weapon or combining two effects together. Also note that each quality has a different effect on how it sells at the shops, for example Poignant makes an item sell for a lot more than others.
Effects
Effects are gained through shards and each has a name and level, such as Attack [2]. Each effect does something different, for example Attack [2] gives a Physical Attack +17 to the item. The higher the level, the more it gives.
Dualizing Effects
When you are dualizing a shard into an equipment you may have different outcomes when it comes to the effects:
- If you dualize an equipment with no effects already on it, the shards effect will be added to the equipment.
- If you dualize an equipment with a shard of the same effect already on the gear, you will gain the higher effect or gain a level if they have the same level.
- Example: The equipment you are dualizing has a Defense [2] and you choose a Defense [5] shard, you will get Defense [5]. On the other hand, if you dualize a Defense [2] with another Defense [2], you get a Defense [3] effect.
- once in a while you may actually get a whole new effect from dualizing two effects.
- Example: Resist + Evade + Vigorous = Paladin
Tempering
Once an equipment has been dualized it can not be dualized with another shard until you temper and extract the Gem. In order to do this you will need to equip the weapon and participate in battle until it is tempered. You will know when a piece of equipment is tempered because it will be listed in orange instead of blue. Blue means it has been dualized to a shard, but has not been tempered. In order to dualize another shard into a piece of gear you will need to dualize two tempered equipments and extract a Gem from the two highest effects on each piece.


