Elements
The Magic System in Chrono Cross uses Elements. There are six element categories: Yellow, Green, Blue, Red, Black and White.
Each character has element slots. You must equip elements into the slots to use them in battle. Each element can be used only once in each battle, with the exception of Consumable Elements which can be used until you have no more of that element in stock.
Each character has their own innate elemental colour. Elements react differently to each other, similar to elemental properties in many games. For example, Black is strong against White. Serge has an innate colour of White, so he is more vulnerable to Black attacks. Also, elements have increased strength when they are used by someone of their innate colour. So if Serge uses a white element, it will have a stronger effect then if Kid (Innate Red) uses the same element.
Each Spell has a number associated with it. This indicates the levels on the Element Slots where they can be placed. For example, if an element has the value 3 +/- 2 then the element is made for slot level 3. The +/- 2 part means that the element can be put 2 levels up or down from 3. So if the element is placed in level 1 or 2, it will still work, but it will be a little weaker. If it is placed in level 4 or 5, it will be a little stronger. You could not put this element in level 6, because it can only go up by 2. It's easier to understand when you play the game a little. Some elements have a set position. [7 +/- 0]
High level spells go in high level slots. Throughout the game you'll earn more slots to put your elements in. Some elements require you to be of the same innate colour to be used.
If you notice in battle, there is a Field Effect indicator in the upper left. This shows the colour of the last three elements used. When this indicator shows a single colour in all three parts, elements of that colour will be increased. To use a Summon Element, the field indicator must be completely filled by the summon's colour. Some elements can change the colour of the field: for example GreenField will change the entire Field Effect to green.