Large spikes of magically strengthened ruby rain towards the ground in a cylindrical area of your choice which can be up to 20 feet in radius and up to 40 feet high. This area is centred on a point you target that you can see and is within range. Each creature in the area must make a Dexterity saving throw. Creatures that fail the saving throw take 2d8 piercing damage while creatures that succeed take half as much damage. 

Any ground within the area becomes covered in ruby spikes that remain until the end of your next turn at which point they vanish. While the ground has these spikes it is considered difficult terrain and any creature that moves 1 or more feet across this ground receives 2 piercing damage for every foot they move. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the piercing damage from the ruby rain increases by 1d8 for each slot level above 3rd (the damage from the spikes in the ground remains the same).