Certain cards in Magic have effects that can change the text of other cards. Card with these text-changing effects are informally known as hacks or word-changers.
Text-changing effects replace each instance of a characteristic, of a permanent or of a spell, with another of the same genus (e.g., color) or type (e.g., basic land subtype, creature subtype). Text-changing effects are considered exclusively within blue magic according to the historic and current understanding of the color pie, and all cards with a text-changing effect to date have been blue.
The term "hacks" has been recognized by at least Fifth Edition, by the Glossary of the Official Strategy Guide (5th Edition).
From the Comprehensive Rules (Guilds of Ravnica (January 25, 2019))
- 612. Text-Changing Effects
- 612.1. Some continuous effects change an object's text. This can apply to any words or symbols printed on that object, but generally affects only that object's rules text (which appears in its text box) and/or the text that appears in its type line. Such an effect is a text-changing effect.
- 612.2. A text-changing effect changes only those words that are used in the correct way (for example, a Magic color word being used as a color word, a land type word used as a land type, or a creature type word used as a creature type). An effect that changes a color word or a subtype can't change a card name, even if that name contains a word or a series of letters that is the same as a Magic color word, basic land type, or creature type.
- 612.2a Most spells and abilities that create creature tokens use creature types to define both the creature types and the names of the tokens. A text-changing effect that affects such a spell or an object with such an ability can change these words because they're being used as creature types, even though they're also being used as names.
- 612.3. Effects that add or remove abilities don't change the text of the objects they affect, so any abilities that are granted to an object can't be modified by text-changing effects that affect that object.
- 612.4. A token's subtypes and rules text are defined by the spell or ability that created the token. A text-changing effect that affects a token can change these characteristics.
- 612.5. One card (Volrath's Shapeshifter) states that an object has the "full text" of another object. This changes not just the text that appears in the object's text box and type line, but also changes the text that represents its name, mana cost, color indicator, power, and toughness.
- 612.6. One card (Spy Kit) states that an object has "all names of nonlegendary creature cards." This changes the text that represents the object's name. That object has the name of each nonlegendary creature card in the Oracle card reference. (See rule 108.1.)
From the glossary of the Comprehensive Rules (Guilds of Ravnica (January 25, 2019))
- Text-Changing Effect
- A continuous effect that changes the text that appears in an object's text box and/or type line. See rule 612, "Text-Changing Effects."
List of text-changing effects[edit | edit source]
As of Dragon's Maze, four (4) cards can change a color word to another:
Note that this ability is functionally different from those of color changers.
Basic land subtype "hacks"[edit | edit source]
As of Dragon's Maze, one (1) card can change a basic land subtype to another:
Color word and/or basic land subtype "hacks"[edit | edit source]
As of Dragon's Maze, five (5) cards can change a color word to another or a basic land subtype to another:
As of Dragon's Maze, one (1) card can change a creature subtype with another:
- Champions of Kamigawa featured Swirl the Mists, an enchantment that can replace all instance of color words in the text of spells and permanents with a chosen color word, chosen as it enters the battlefield.
- Unhinged featured Magical Hacker, a creature that can replace plus ("+") signs in text boxes with minus ("−") signs and vice versa.