Defensive Bubble

You cast an blue tinted bubble around you protecting you and possible allies from incoming damage. The bubble extends out from you for 20 feet in a sphere and has a 40 hit points, once the bubble has lost all of its hit points it is destroyed. While you are inside of it you can't attack anyone who is outside of bubble and no one can attack you in the bubble with ranged attacks, but if an enemy creature steps in the bubble you have advantage on the creature as long as he is in the bubble.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher the bubble gains an additional 20 hit points for each slot used.