Mechanic

A mechanic is a card ability that can be used on multiple cards. The word mechanic has no meaning in the Comprehensive Rules, it's merely a design concept.

Categories
Mechanics are typically categorized as follows:
 * Keyword abilities or often shortened to "keywords": words attached to rules text, that represent an ability that is constant. They come with reminder text, except if they are evergreen.
 * Keyword actions: verbs that have a special rules meaning. Sometimes reminder text summarizes their meanings.
 * Ability words are words that group cards that have a common functionality and do not imply any particular rules.
 * mechanics that are not clearly classified.

Keywords abilities and keyword actions are closely related. Both represent a longer segment of rules text and may allow variable costs and effects. Because they have a specific rules meaning and are listed in the Comprehensive Rules, keywords of either type can be referenced from other cards. They differ in that keyword abilities are either characteristics of objects or are objects themselves, whereas keyword actions describe game-related actions.

For example, the keyword ability enchant, as in Enchant creature, states a restriction on the valid targets for an aura. The related keyword action attach describes the process of physically putting such an aura onto its target.

Ability words have no rules meaning, but exist to name and flavorfully link otherwise unnamed mechanics. Like flavor text, ability words are italicized. Because they have no rules meaning, and are not listed in the Comprehensive Rules, ability words are never referenced on other cards.

Parasitic
A mechanic is considered parasitic when it only interacts with other things in a particular set rather than the rest of Magic. Examples are horsemanship and splice onto Arcane.

Linear
R&D talks about things being “linear” in that they dictate other cards mechanically. Colorless matters is very linear in that it dictates having cards to provide the colorless mana.
 * “Anti-linear” means the opposite. The more cards with the same mechanic you have, it gets worse. Examples are atogs, processors, delve and heroic.

Modular
Modular design elements are not dependent on other design elements.

Scaling
A scaling mechanic is any mechanic that can exist at different levels and thus must be designed to have its effects work at a variety of scale.

An effect that scales by number is something where the effect involves a number and some element can change what that number is. Examples of scaling by number are domain, an X spell or party. An effect that scales by volume is one where a basic effect can be copied numerous times. Examples of scaling by volume are replicate or multikicker.