Legend (Obsolete)
Many creature cards were printed with the creature type "Legend." All of these cards have been given errata to have the legendary supertype. Legend is no longer a creature type. See Legendary.
Legendary
Legendary is a supertype that may apply to any type ("Legendary Land," "Legendary Artifact," and so on).
If two or more legendary permanents with the same name are in play, all are put into their owners' graveyards. This "legend rule" is a state-based effect. See rule 420.5.
If a legendary permanent's types or subtypes change, this doesn't change its supertypes. The permanent will still be legendary.
Lethal Damage
Lethal damage is an amount of damage greater than or equal to a creature's toughness. A creature with lethal damage, but greater than 0 toughness, is destroyed. This is a state-based effect. See rule 420.5.
Library
The library is the zone from which a player draws cards. When a game begins, each player's deck becomes his or her library. See rule 217.2, "Library."
Life, Life Total
Life total is a sort of score. Each player starts the game with 20 life. Any increase in a player's life total is considered to be gaining life. Any decrease in a player's life total is considered to be losing life. A player whose life total drops to 0 or less loses. This is a state-based effect. See rule 420.5.
LIFO (Informal)
An acronym for "Last In, First Out," LIFO is the order in which spells and abilities resolve after going on the stack. The last played is resolved first. See rule 409, "Playing Spells and Activated Abilities," and rule 413, "Resolving Spells and Abilities."
Limited Range of Influence
Limited range of influence is an optional rule used in some multiplayer games. A player's range of influence is the maximum distance from that player, measured in player seats, that the player can affect. Players within that many seats of the player are within that player's range of influence. Objects controlled by players within a player's range of influence are also within that player's range of influence. Range of influence covers spells, abilities, effects, damage dealing, attacking, and making choices. See rule 601, "Limited Range of Influence Option."
The limited range of influence option is always used in the Emperor variant (see rule 607), and it's often used for games involving five or more players.
Local Enchantment (Obsolete)
Some older cards used the term "local enchantment" for enchantments that are attached to other permanents while they're in play. These cards now have the Aura subtype.
Lose the Game
There are several ways to lose the game. A player can concede the game at any time; a player who concedes loses the game immediately. If a player's life total is 0 or less, he or she loses the game the next time a player would receive priority (this is a state-based effect; see rule 420). If a player attempts to draw a card from an empty library, he or she loses the game the next time a player would receive priority (this is a state-based effect; see rule 420). If a player has ten or more poison counters, he or she loses the game the next time a player would receive priority. (this is a state-based effect; see rule 420). If a player would both win and lose simultaneously, he or she loses. In a multiplayer game between teams, a team loses the game if all players on that team have lost. See rule 102, "Winning and Losing."
Madness
Madness is a keyword that represents two abilities. "Madness [cost]" means "If a player would discard this card, that player discards it, but may remove it from the game instead of putting it into his or her graveyard" and "When this card is removed from the game this way, its owner may play it by paying [cost] rather than paying its mana cost. If that player doesn't, he or she puts this card into his or her graveyard." See rule 502.24, "Madness."
Main Game
Some cards allow players to play a Magic subgame. The "main game" is the game in which the spell or ability that created the subgame was played. See rule 506, "Subgames."
Main Phase
The term "main phase" comprises the first main and second main phases, also called the "precombat" and "postcombat" main phases. Artifact, creature, enchantment, and sorcery spells may be played only by the active player during his or her main phase, and only when the stack is empty. A player may also play one land each turn during his or her main phase.
Mana
Mana is the energy used to play spells and is usually produced by lands. Mana is created by mana abilities (and sometimes by spells), and it can be used to pay costs immediately or can stay in the player's mana pool. See rule 406, "Mana Abilities."
Colored mana costs, represented by colored mana symbols, can be paid only with the appropriate color of mana. Generic mana costs can be paid with any color of, or with colorless, mana. See rule 104.3.
The spell or ability that adds mana to a mana pool may restrict how it can be used. An ability might produce mana that can be used only to play creature spells or only to pay activation costs.
The type of mana a permanent "could produce" is the type of mana that any ability of that permanent can generate, taking into account any applicable replacement effects. If the type of mana can't be defined, there's no type of mana that that permanent could produce. The "type" of mana is its color, or lack thereof (for colorless mana).
Mana Ability
A mana ability is either activated or triggered. A mana ability doesn't go on the stack-it resolves immediately. See rule 411, "Playing Mana Abilities."
A player may play an activated mana ability whenever he or she has priority and whenever a rule or effect asks for a mana payment. This is the only type of ability that can be played in the middle of playing or resolving a spell or ability. See rule 406, "Mana Abilities."
Mana Burn
When a phase ends, any unused mana remaining in a player's mana pool is lost. The player loses 1 life for each mana lost this way. This is called "mana burn." See rule 300.3.
Mana Cost