The Fellport Watch keep bundles of these heavy arrows ready for use along the walls and spires of the city to deter flying invaders. Their distinctive heads attract iron as all lodestones do. The standard Watch arrows all have black fletching with a grey cock feather, though other variations certainly exist.
When fired at an opponent wearing metal armor, these arrows grant a +1 bonus to hit. On a hit, the target must roll a DC 13 Constitution saving throw. On a failed saving throw, the target's fly speed drops to zero for two rounds, and they start falling from the sky, but they also gain resistance to lightning damage.
Most armorers and all transmutation students at the college know how to make Arrows of Grounding. The Fellport Watch pays well to keep these arrows in abundant quantities, as the city has very little in the way of air defenses otherwise. Nobody knows who initially came up with the formula, but historical records in Fellport mention them as far back as the Middle Imperial period, about 400 years ago.