Rockslide Spell

You enhance your spell with elemental earth, causing chunks of stone to litter the ground. If the next action you use is to Cast a non-cantrip Spell that affects an area, a number of 5-foot squares in the area equal to the spell rank become difficult terrain for 1 round. These squares must be on the ground, and the entire area of difficult terrain must be contiguous. The spell gains the earth trait.