When cast, this spell charged a wizard's sling with magical energy, causing it to transform mundane ammunition into magic missiles over a matter of a several seconds. These missiles were affected by any items, spells or abilities that affected typical magic missiles however they were capable of penetrating the defenses of the abjuration spell shield.
The number of projectiles that could be transformed and released under a single casting of slingstar increased depending on the power and experience of the caster.
In addition to a verbal components, slingstar used the motion of the caster whirling their sling as a somatic component. Its material component consisted of any stones or bullets that were fired during the spell's duration.