Volatile Flames

You create an unstable ball of fire, from which three darts of fire erupt. Each dart can target a creature of your choice that you can see within range. Make a ranged spell attack for each dart. On a hit, the dart does 2d4 fire damage.

If the attack roll scores a critical hit, the dart does 5d4 fire damage instead of the 4d4 fire that you would normally get on a critical hit.

However, If any attack roll is a natural one, the ball of fire used to cast the spell is too unstable and immediately explodes on cast. All darts miss their target and the caster takes 1 fire damage per dart of fire that would have been cast.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the spell creates one more dart for each slot level above 1st..