One of the new mechanics added in the new Spellfire is the Five New Elements. They are attributed to all-new cards and all new states of the cards. The element of the card is visible in the bottom right corner.
The balanced fight between Fire, Air, Water, Earth, and Ether will make you think very hard when you start building your ultimate deck. No element is more potent or more important than another, and each has its own defined strengths and weaknesses.
All cards in Spellfire world have an assigned element, which you can see in the bottom right corner of the card. The question mark instead of an element marker means that any element of your choice may be assigned to the card. When the element is not known, treat the card as a non-effective card in any game situation.
For more information about the balance and meanings of the elements, read the school section:
The importance of elements in Spellfire