Synthesis.

You can obtain a recipe then find ingredients to create items. Items serve just a few purposes but i know everyone is excited to work toward the Ultima. However, there can only be 1 ultima at a time. It will look difference depending on who's using it but you can be sure it's not to be ignored. 

You're first thre free recipes are: Potion, Chain, and Bracelet. 

Currently everyone has 3 item slots that are all a mix of item, accessory, and armor slots. What's important is that you consider the utility of your things and the number of slots you have.

Items are like techniques, but activating once.

Accessories and Armor are like Passives.

A few rare items will act like Limits and Autos.

Uh anyway the recipes.

Potion: any shard + 1 MP point. Simple and effective. A potion heals a small portion of your health.
Chain: any stone + 1 MP point. Simple and small. A chain that enhances your defense through a charm.
Bracelet: any gem + 1 MP point. Simple and empty. A bracelet that allows a for resistance toward 1 element provide you place a material inside the slot. 

As you can see this is an extremely simple synthesis method. You also pay in MP points. Each character is capable of spending 1 MP point per synthesis also only 1 MP point per day. You can find new recipes or experiment with materials and MP points if you'd like. However, I don't recommend using the wiki. As an anti-"cheat the gm cause info is wide spread" if you don't know a recipe in character but its something from the games then you may discover it doesn't work the same way or is much weaker. In many cases you won't have enough MP points to cover the cost of synthesis.

Also I will be using KH2 materials. Their drop rates are similar to those of the enemies of KH2 but I'll be adding much more cause it's not that easy to obtain many materials when you're in a forum RP. 

Lucky Lucky will have a standard effect which I'll define now.

Lucky Lucky: Passive. Luck is increased for the drop rates of certain materials. From 1 to 7 able to affect the party as a whole, increase listed drop rates of materials by 10% per Lucky Lucky passive in the party. This means anything 100% or more will drop. It is possible to obtain more than 1 drop from the same enemy under a certain condition.
[indent]That condition is simple, while you have 3 or more Lucky Lucky passives in the party the mechanic for randomized dropping changes. Normally a small die is rolled to determine which item is dropped from an enemy then a percentile is rolled to see if the drop occurs. For each Lucky Lucky Passive after 3, that small die roll is repeated. Therefore the maximum number of items dropped is 4.[/indent]

Remember Lucky Lucky is a party wide effect. If everyone in the party has 1 Lucky Lucky passive then it's maxed out with no need of anyone taking a second Lucky Lucky Passive. If the party separates then Lucky Lucky will treat the parties as two different entities therefor separate groups need more Lucky Lucky passives.

There's something else I need you to know. 

Stats don't exist, so things that increase attributes of a character are not measurable. "Increases speed, Increases Resistance, Increases Defense" don't have a real meaning so that's up to you to write into your character's perception. Over time you'll notice formerly strong enemies are weak, this is due to character growth and your items together. I wont be making a huge distinction between having items and not having them so they aren't going to save you unless they have abilities that matter.