Beakered Lightning

You conjure a six-inch glass sphere covered in arcane runes, piercing jolts of electricity fill the space within. As part of the action used to cast the spell you can propel the sphere to a point within range, where it releases the lightning in a 10-foot-radius sphere. Each creature within the area must make a Dexterity saving throw. On a failed save, a creature takes 3d6 lightning damage and can't take reactions until the start of their next turn. On a successful save, it takes half as much damage and can use reactions. 

You can refrain from propelling the sphere after completing the spell, if you wish. The sphere can be normal size or the size of a sling stone and lasts until you take a long or short rest. At any time, you or a creature you give the sphere to can throw the sphere (to a range of 40 feet) or hurl it with a sling (to the sling’s normal range). It releases the lightning on impact, with the same effect as the normal casting of the spell. You can also set the sphere down without releasing lightning from it. After 1 minute, if the sphere hasn’t already released, the lightning springs out.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.