A mnemonic device used within the context of Magic: The Gathering, DEBT is an acronym used to explain the concept of the Protection keyword ability, and describes the circumstances in which the object with protection is granted immunity from certain effects based on specified qualities, such as color or card type.
  • Damage: The protected permanent or player cannot be damaged by the thing it has protection from.

  • Enchant/Equip: The protected permanent or player cannot be enchanted, equipped, or fortified by anything with the specified quality, and any such enchantments or equipment with the property it is protected from that are already attached will fall off, barring specific instructions otherwise.

  • Block: The protected permanent or player cannot be blocked by creatures that have the specified quality it is protected from.

  • Target: The protected permanent or player cannot be targeted by spells or abilities from sources with the specified quality. See also: hexproof (CR 702.11.); shroud (CR 702.18.).

For example, a creature with protection from black, abbreviated "pro black", cannot be damaged by black spells; enchanted by black auras or equipped with black artifacts; blocked by black creatures; or targeted by black abilities. Objects with multiple colors are protected from as well as long as the color protected from is one of its colors. There are even, currently, seven cards that have, can gain, or grant protection from everything (CR 702.16j): Hexdrinker, Perch Protection, Progenitus, Teferi's Protection, The One Ring, The Stasis Coffin, and Vexilus Praetor.