Effects that use the word "instead" are replacement effects. Most replacement effects use the word "instead" to indicate what events will be replaced with other events. See rule 419, "Replacement and Prevention Effects."
Interrupt (Obsolete)
Some older cards used the term "interrupt" on the card"s type line. All interrupt cards are now instant cards. All abilities that were played as interrupts are now played like normal activated abilities (and are mana abilities if they produce mana).
Intervening "If" Clause Triggered abilities with a condition directly following the trigger event (for example, "When/Whenever/At [trigger], if [condition], [effect]") check for the condition to be true as part of the trigger event; if it isn"t, the ability doesn"t trigger. The ability checks the condition again on resolution. If it"s not satisfied, the ability does nothing. Note that this mirrors the check for legal targets. Note that this rule doesn"t apply to any triggered ability with an "if" condition elsewhere within its text. See rule 404.3.
Island
"Island" is one of the five basic land types. Any land with the land type Island has the ability "{T}: Add {U} to your mana pool." See rule 212.6d.
Islandcycling
See Landcycling.
Islandhome (Obsolete)
Some older cards were printed with the term islandhome, which means "This creature can"t attack unless the defending player controls an Island" and "When you control no Islands, sacrifice this creature." Cards that previously had islandhome now simply have the two parts of islandhome written out without using the keyword.
Islandwalk
See Landwalk.
Keyword Ability
Some abilities are very common or would require too much s.p.a.ce to define on a card. These abilities list only the name of the ability as a "keyword"; sometimes reminder text summarizes the game rule. See rule 502, "Keyword Abilities."
Kicker
Kicker is a keyword ability with a cost and an effect. Paying a spell"s kicker cost causes the spell to have an additional or alternative effect. See rule 502.21, "Kicker."
"Kicker [cost]" means "You may pay an additional [cost] as you play this spell." You declare whether you intend to pay a spell"s kicker cost at the same time you would choose the spell"s mode (see rule 409.1b), and you actually pay the cost when you pay the rest of the spell"s costs (see rule 409.1f-h). Paying a kicker cost is always optional.
A spell"s controller chooses targets (see rule 409.1d) for a kicker effect only if he or she declared the intention to pay the kicker cost for that effect. If the spell"s controller declared that he or she wouldn"t pay a particular kicker cost, he or she doesn"t choose the targets for the effect a.s.sociated with that kicker cost.
Land
Land is a type. Lands aren"t spells and don"t go on the stack; they are simply played from the hand. The active player may play a land once each turn during his or her main phase when he or she has priority and the stack is empty. If an object is both a land and another type, it can only be played as a land. It can"t be played as a spell. See rule 212.6, "Lands."
Land Type
Land subtypes are always a single word and are listed after a long dash: "Land Locus, Land Urza"s Mine," etc. Land subtypes are also called land types. Lands may have multiple subtypes. Note that "basic," "legendary," and "nonbasic" aren"t land types. See rule 212.6, "Lands." See also Basic Land Type.
The list of land types, updated through the Time Spiral set, is as follows: Desert, Forest, Island, Lair, Locus, Mine, Mountain, Plains, Power-Plant, Swamp, Tower, Urza"s
Landcycling
"Landcycling" is a generic term; a card"s rules text usually names a specific type of land, such as "plainscycling."
Landcycling is an activated ability. "Plainscycling [cost]" means "[Cost], Discard this card: Search your library for a Plains card, reveal it, and put it into your hand. Then shuffle your library." See rule 502.18, "Cycling."
Landwalk
"Landwalk" is a generic term; a card"s rules text will give a specific property to look for, such as "islandwalk."
Landwalk is an evasion ability. A creature with landwalk is unblockable as long as the defending player controls at least one land which has the specified subtype or supertype. See rule 502.6, "Landwalk."
Last Known Information
The last known information about an object is the information that it had just before it left the zone it was in. Effects from resolving spells and abilities use last known information if the object they require information from isn"t in the zone it"s expected to be in (unless the effect divides damage). See rule 413.2f.
Layer
Continuous effects are applied in order, in six layers: (1) copy effects (see rule 503, "Copying Objects"); (2) control-changing effects; (3) text-changing effects; (4) type-, subtype-, and supertype-changing effects; (5) all other continuous effects, except those that change power and/or toughness, and (6) power and/or toughness-changing effects. Inside layer 6, effects are applied in a series of sublayers. See rule 418.5, "Interaction of Continuous Effects."
Leaves Play
A permanent leaves play when it moves from the in-play zone to any other zone (see rule 410.10c) or when its owner leaves the game (see rule 600.4a).
If a token leaves play, it ceases to exist. This is a state-based effect. See rule 420.5.
If a permanent leaves play and later returns to play, it"s treated as an entirely new permanent with no "memory" of anything from its former existence. (Phasing is an exception to this; see rule 502.15, "Phasing." Permanents that phase out also don"t trigger any comes-into-play or leaves-play abilities.)
Legal Text
Legal text (the fine print at the bottom of the card) lists the copyright information. It has no effect on game play. See rule 210, "Legal Text."