Advanced rules: element of spells
The game is called ELEMENTAL right? So obviously there is a rule for elemental weaknesses and strengths!
Here is the classic weakness/strength cycle:
water is strong against fire and weak to earth
fire is strong against air and weak to water
air is strong against earth and weak to fire
earth is strong against water and weak to air
And here is how you can use that at you own advantage: if a player plays a spell with a base element that is weak against the base element of the opposing spell, that player cannot use that element during his next turn. This effect still apply even if the spell with the strong base element is neutralized or reflected.
Eg:
Attack:
Base
Trigger
Defense:
Base
Trigger
In this case water is strong against fire. The attack spell is neutralized and the attacking player will not be able to use the fire element during his next turn.
That's a huge incentive to use a base element for a spell that is strong against the base element of the opposing spell because you will know that that player is not going to use a particular element during his next turn. Obviously there is always a downside and a choice to be made: maybe if you use an element as a base because of his elemental strength you will not be able to defend against all damage of a spell, or maybe you will not be able to characterize your spell with that element. It's up to you to decide what will benefit you the most!