Shield Magic is the name of two different magics in the series.
Ghouls 'n Ghosts (Sega Master System)[]
Shield Magic is one of the magics that Arthur can obtain. It uses 2 points from the magic gauge to create two barriers that temporarily makes Arthur invincible.
Super Ghouls 'n Ghosts[]
Shield Magic is the Torch's magic, which creates three energy orbs to temporarily protect Arthur.