Static Charge

3rd-Level Ranger Feature

You've learned to channel volatile lightning magic into your weapons. Whenever you hit a creature with a melee weapon attack, you build up a single charge of electrical energy called a Static Charge. You may store a number of Static Charges equal to your ranger level If you do not gain a new Static Charge after 1 minute has passed, you lose all Static Charges you've stored.
When you hit a creature with a weapon attack, you can choose to forgo gaining a Static Charge and instead cause a burst of electricity. When you do so, you expend all of your Static Charges and deal ld4 lightning damage for each Static Charge expended this way. A creature that takes this damage must succeed a Constitution saving throw or reduce their speed by 5 feet for each expended Static Charge until the end of that creature's next turn.