thumb|300px|Units casting abilities in formation. The magical box, or magic box, is a micromanagement technique in StarCraft. It enables multiple spellcasters to unleash their spells at the same time, but in slightly different areas of the screen.
If spellcasting units of the same type are put into a small "box", the units will move in formation and cast spells in formation. The spells must be targeted "outside" second box, otherwise they will clump together.
Magic boxes work best with small numbers of casters, such as four vultures or high templar.
In StarCraft II, a "magic box" is used to keep air units (especially mutalisks) spread out flying in formation, used when engaging a unit that has an anti-air AOE attack (such as the thor or archon). By keeping the units spread out, splash damage is largely negated.
Skyglow1, Gatsu. 2005-11-18. Magical Boxes: Key to Spreading Spells. Teamliquid. Accessed 2009-02-28.