A replacement effect is a type of continuous effect that “watches” for a specified event and replaces it with a different one. See rule 419, “Replacement and Prevention Effects.”
Replicate is a keyword that represents two abilities. The first is a static ability that functions while the spell is on the stack. The second is a triggered ability that functions while the spell is on the stack. “Replicate [cost]” means “As an additional cost to play this spell, you may pay [cost] any number of times” and “When you play this spell, if a replicate cost was paid for it, copy it for each time its replicate cost was paid. If the spell has any targets, you may choose new targets for any number of the copies.” See rule 502.52, “Replicate.”
A requirement to attack or block is any effect that forces one or more creatures to attack or block. All attacks and blocks must still be legal. See rule 500, “Legal Attacks and Blocks.”
When a spell or ability on top of the stack resolves, its controller carries out the instructions printed on the card, in the order written. When combat damage resolves, it’s dealt as previously assigned to the fullest extent possible. See rule 413, “Resolving Spells and Abilities.”
A player can choose to play an instant spell or activated ability when something else is already on the stack, rather than waiting for the earlier spell or ability to resolve first. The spell or ability is said to be played “in response to” the earlier spell or ability. See rule 408, “Timing of Spells and Abilities.”
A restriction on attacking or blocking is any effect that could prevent a creature from attacking or blocking. All attacks and blocks must still be legal. See rule 500, “Legal Attacks and Blocks.”
To reveal an object is to show that object to all players. If a one-shot effect reveals a card, the card is returned to its former state after all players have seen it. If the cost to play a spell or ability includes revealing a card, the card remains revealed from the time the spell or ability is announced until it leaves the stack.
Ripple is a triggered ability that functions only while the card with ripple is on the stack. “Ripple N” means “When you play this spell, you may reveal the top N cards of your library, or, if there are fewer than N cards in your library, you may reveal all the cards in your library. If you reveal cards from your library this way, you may play any of those cards with the same name as this spell without paying their mana costs, then put all revealed cards not played this way on the bottom of your library in any order.” See rule 502.56, “Ripple.”
An object’s rules text defines many of that object’s properties. Changing an object’s rules text changes the object’s properties.
To sacrifice a permanent, its controller moves it from the in-play zone directly to its owner’s graveyard. A player can’t sacrifice something that isn’t a permanent, or something that’s a permanent he or she doesn’t control. If an effect instructs a player to sacrifice a permanent that he or she doesn’t control, nothing happens. Sacrificing a permanent doesn’t destroy it, so regeneration or other effects that replace destruction can’t affect it.
Scry is a static ability that functions while a spell or ability is resolving. “Scry N” means “Look at the top N cards of your library. Put any number of them on the bottom of your library in any order and the rest on top of your library in any order.” See rule 502.36, “Scry.”
For sealed deck or draft play, only forty cards are required in a deck, and a player may use as many duplicates of a card as he or she has. Each player still needs small items to represent any tokens and counters, and some way to clearly track life totals. See rule 100.3.
If you’re required to search a zone not revealed to all players for cards of a given quality, such as type or color, you aren’t required to find some or all of those cards even if they’re present; however, if you do choose to find cards, you must reveal those cards to all players. Even if you don’t find any cards, you are still considered to have searched the zone.
If you’re simply searching for a quantity of cards, such as “a card” or “three cards,” you must find that many cards (or as many as possible). These cards often aren’t revealed.
Example: If an effect causes you to search a player’s library for all duplicates of a particular card and remove them from the game, you may choose to leave some of them alone, but if an effect causes you to search your library for three cards and it contains at least three, you can’t choose less than three.
To set aside a card is to remove it from the game; however, the effect will specify some condition that allows the set-aside card to return to the game. See also Removed from the Game.
Shadow is an evasion ability. Attacking creatures with shadow can’t be blocked by creatures without shadow, and attacking creatures without shadow can’t be blocked by creatures with shadow. See rule 502.8, “Shadow.”
The Two-Headed Giant multiplayer variant uses a shared life total. Each two-player team’s life total starts at 40, and the team loses if its life total reaches 0. Damage, loss of life, and gaining life happens to each player individually. The result is applied to the team’s shared life total. If an effect needs to know the value of any individual player’s life total, that effect uses the team’s life total divided by the number of players on the team (rounded up) instead. See rule 606, “Two-Headed Giant Variant.”
Replacement and prevention effects act like “shields” around whatever they’re affecting. See rule 419, “Replacement and Prevention Effects.”
To shuffle a deck, library, or pile is to make the order of that deck, library, or pile random. After a player shuffles a deck, library, or pile he or she owns, each opponent has the option to shuffle or cut that pile. See rule 101.1.
To skip an event, step, phase, or turn is to proceed past it as though it didn’t exist. Skipping an event, step, phase, or turn is a replacement effect. “Skip [something]” is the same as “Instead of doing [something], do nothing.” See rule 300.9 and rule 419.6e.