Magic the Gathering: The Dark (Base Set) card 100 Dark Sphere

*Name: Dark Sphere
Type: Artifact
Play Cost: 0 Colorless
Game Text: T: Sacrifice Dark Sphere to prevent half of the damage done to you by a single source, rounded down.
Card Text: "I was struck senseless for a moment, but revived when the strange curiosity I carried fell to the ground, screaming like a dying animal." -Barl, Lord Ith
*Source: Front of card