Loops A few slight changes have been made to the rules for handling unbounded loops. Now, if a loop requires two or more players to do things to keep the loop going, each player chooses a number of times they wish to do their part to keep it going. Note that these decisions are made in turn order, with each player knowing the number chosen by the previous player. Then the loop is played out as though each player performed their appropriate actions the number of times they specified.
Also, if a loop contains an effect which specifies "[X] unless [Y]," where X and Y are each actions, no player can be forced to choose Y in order to break the loop. If nobody chooses to perform Y, the loop continues as though X were mandatory.
Keyword Abilities Shards of Alara introduced three new keywords; for more information on any of them, see their entries in the Keyword FAQ.
Devour is an ability that allows you to sacrifice your creatures in order to make the creature that devoured them stronger; many creatures with devour also give you some bonus that gets better with each additional creature you devour.
Exalted is an ability that encourages you to choose a single "champion" to attack with--whenever a creature you control attacks alone, it gets +1/+1 for every permanent with exalted you control.
Unearth is an ability that allows your creatures to come back from the graveyard for one last stab at your opponent. Activate the unearth ability to return your creatures from your graveyard to the battlefield and give them haste--they get exiled at the end of the turn, but your opponent is already dead by then, right?
Entering the Battlefield attacking/blocking This update has introduced a new rule to prevent weird things from happening with the new card Gather Specimens . If a creature would enter the battlefield attacking under the control of a player who isn't attacking, it enters the battlefield, but isn't attacking. Similarly, if a creature would enter the battlefield blocking but wouldn't be blocking a creature attacking its controller or one of their planeswalkers, it enters the battlefield, but isn't blocking anything.
Replacement effects and entering the battlefield An small addition has been added to the rules for replacement effects, again to prevent weird things from happening with Gather Specimens . When applying replacement effects, you must apply self-replacement effects first (effects belonging to a spell or ability that would replace some part of its own effect), then effects that would change whose control something enters the battlefield under, and then the rest in any order you wish, so long as they're still applicable.
Clarifications A few small clarifications were made to the rules with this update; these clarifications cause no functional changes, but you may wish to be aware of them anyway.
The procedure for conceding the game has been clarified; when a player concedes, they leave the game first, then lose. They don't lose before they leave.
This update has clarified the distinction between the act of attacking and/or blocking alone (being the only creature declared as an attacker or blocker) and the condition of attacking and/or blocking alone (being the only attacking or blocking creature).
Also clarified was the fact that the abilities that form the instructions you follow when instant or sorcery spells resolve are not activated, triggered, or static abilities, but another kind entirely, called spell abilities.
If two or more state-based actions are trying to do the same thing, and something would replace that thing with something else, it replaces all of them.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
Playing with Cards Revealed - Reversal! This update changed some (very corner-case) interactions with cards that reveal and interact with the top card of the library; now, if that card stops being revealed for any length of time (including as short a period as shuffling your library or rearranging the top few cards), it's considered a "new" card.
Deck-Construction-Modifying Abilities Previously there were some technical issues with abilities that modified the rules of deck construction; the rules have been altered slightly so as to allow them to work properly. This causes no functional change for players; it's just that the cards now have the proper CompRules support to let them work the way they need to.
[Type]cyling The rules for [type]cycling are being expanded to handle "basic landcycling". This doesn't change the functionality of any existing cards.
"Could Produce" A new rule has been created to clarify what a card means when it's talking about what type of mana something "could produce". This causes no functional changes; the entry is simply being copied from the glossary into the CompRules proper.
Order of Copy Creation If two or more objects that are being put onto the stack at the same time, their controller chooses their order relative to each other.
Play-Restrictions and Borrowing A new rule has been created to clarify some interactions between things with abilities that have some restriction and things that that "borrow" those abilities from other cards.
Clarifications A few small clarifications were made to the rules with this update; these clarifications cause no functional changes, but you may wish to be aware of them anyway.
The rules for basic land types were reworded slightly to make it clear that they apply to even lands that aren't on the battlefield.
The step-by-step instructions for how an object changes zones have been reworded so that they actually work with cards that may have abilities that affect how they do so from a hidden zone. This causes no functional changes.
The rules for creatures and planeswalkers in combat have been reworded slightly for clarification and to correct some minor omissions.
The rules for triggered abilities are being modified slightly to clarify the differences between them and activated abilities.
A rule has been added to clarify how things that trigger on a player losing the game work.
A rule has been added to clarify what "protection from everything" means.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
Keyword Abilities Alara Reborn introduced a new keyword: Cascade; for more information, see its entry in the Keyword FAQ
Cascade is an ability that gives you a free bonus spell from your library when you cast the card it's on. When you cast a spell with cascade, you exile cards from the top of your library one by one until you exile a nonland card with converted mana cost less than the cascade spell. You then may choose to cast that spell without paying its mana cost. (No matter what type it is.) The exiled cards are put on the bottom of your library in a random order. Best of all, if the spell you cascaded into also has cascade, that spell's cascade triggers and you get to do it all over again!
Becoming a New Object The rules that relate to an object becoming a new object when it changes zones have been changed slightly, with a slight addition to the list of exemptions to allow certain cards to have nicer, more intuitive text. Abilities of a permanent that require information about the choices made when it was played refer to the spell the permanent used to be, and abilities that allow you to cast a spell continue to exist while it's a spell on the stack.
0 Power in Combat - Reversal A creature with 0 power in combat used to not assign any damage in combat, but this caused some minor unintuitive interactions, so they've changed it; now, a creature with 0 power assigns combat damage like any other creature...it just assigns 0 damage. (This means it will deal no damage at all, which is the same as not dealing damage.)
Hideaway There's been a slight change in the rules for the Hideaway keyword to eliminate a confusing loophole.
Clarifications A few small clarifications were made to the rules with this update; these clarifications cause no functional changes, but you may wish to be aware of them anyway.
An addition was added to the rules for "leaves the battlefield" abilities clarifying that something that triggers when an object is put into a graveyard "from anywhere" is never a leaves-the-battlefield ability.
A slight addition was made to the rules for casting spells and activating abilities to clarify exactly when it was that an object becomes targeted.
The rules for protection have been expanded to include definitions of "protection from ~ and from -" and "protection from all ~". They work the same way, there's just rules supporting them now.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
Combat Damage - Major! Combat damage no longer uses the stack. Combat Damage is assigned at the beginning of the combat damage step of combat and then dealt immediately, without any chance to respond. This means that you can no longer both have your creature deal its combat damage and sacrifice it for some other effect or return it to your hand to save it from the combat damage it would receive. Either the creature is on the battlefield as the combat damage step starts, and thus deals and receives combat damage before you can do anything (and dies, if appropriate, before you can do anything), or you sacrifice/bounce it before the combat damage step and it isn't around to deal combat damage at all.
Note that this changes nothing else about what you can do when during combat. You can still do things after blocking but before combat damage is dealt, you can still do things after combat damage is dealt, you can still do things in between 'first strike combat damage' being dealt and 'regular combat damage' being dealt. The only change is that you can no longer do things with combat damage on the stack, after it is assigned but before it is dealt.
This change comes with an addendum, described in the next point.
Damage Assignment Order If an attacking creature is blocked by multiple creatures, as soon as the block is declared, the attacking player decides in what order he wants to assign lethal damage to the blockers. Then, once the combat damage step rolls around, the attacking player assigns damage among the blockers; he must assign 'lethal damage' to the first creature before any can be assigned to the second, must assign 'lethal damage' to the second before any can be assigned to the third, and so on.
Note that 'lethal damage' is either 'damage equal to the creature's toughness, minus any damage already marked on it', or 'any damage from a source that has deathtouch', not 'damage that would actually kill the creature'.
Also note that the reverse also applies--if the defending player somehow gets his creature to block multiple attackers, he must decide in which order he wants to assign lethal damage to those creatures.
Mana and Mana Burn Mana now empties from your mana pool at the end of every step, not just at the end of every phase. To go along with that, mana burn has been eliminated entirely. Unspent mana no longer causes mana burn when it vanishes--it just disappears with no ill effects.
Mulligans - Reversal The rules for mulligans have changed. Previously, the player who was playing first went through all of his or her mulligans before anyone else did, and then each other player did the same in turn order. This is no longer the case. Instead, each player (in turn order) first decides if they want to take a mulligan, and then everyone who did takes their mulligan simultaneously. Then everyone who took a mulligan this way decides whether or not they want to take another, and those who do again take those mulligans simultaneously. This continues until nobody wishes to take a mulligan any more.
You can't decide to stop taking mulligans and then decide to take one after all at some later point once other people have done some more mulligans--once you decide to keep your hand, you keep it for good.
Terminology Changes Magic 2010 introduced a number of terminology changes for various reasons, including shortening card text and (hopefully) clearing up rules confusions among newer players. Those changes are as follows.
'In Play' --> 'The Battlefield' A lot of players tended to get confused about the difference between 'playing' something and something 'coming into play' or being 'put into play', because "play" meant something entirely different when it was being used as a noun and when it was being used as a verb. The former referred to the game zone known as the 'in play zone', while the latter referred to the action of putting a spell onto the stack and paying its costs before giving people a chance to respond to it. (Except for lands, which just entered play when played...which just made things more confusing.) As such, the 'in-play zone' has been renamed 'the battlefield'. This is purely a cosmetic change; anything that talked about 'coming into play' now talks about 'entering the battlefield', and so on.
'Play' --> 'Cast / Activate' As just stated, the act of 'playing' a spell was often confused with 'putting [it] into play', when the two were very different. To help solve this problem, R&D is restoring a bit of old terminology; you now 'cast' spells and 'activate' abilities, not 'play' them. 'Play' now refers only to the act of placing a land onto the battlefield as your one land for the turn.
'Remove(d) from the game' --> 'Exile(d)' The (highly inaccurately named) 'removed-from-the-game zone' has been renamed the 'exile zone', in order to cut down on card text and give it a better name. The act of removing something from the game is now called 'exiling' it. Unmake , for example, now reads "Exile target creature." This creates exactly one functional difference, which is discussed below.
'At end of turn' --> 'At the beginning of the end step' A lot of people got confused about the difference between an effect that lasted 'until end of turn' and something which caused something to happen 'at end of turn', which really meant 'at the beginning of the end-of-turn step'. As such, the name of the 'end-of-turn step' is being changed to the 'end step', and cards which said 'at end of turn' will now say 'at the beginning of the end step' or 'at the beginning of the next end step'. This is purely a cosmetic change and introduces no functional changes.
Lifelink - Reversal! The way that the keyword lifelink works has changed. Rather than being a triggered ability that triggered on damage being dealt, lifelink now changes the nature of the damage that would be dealt by the creature with lifelink. Damage dealt by a source with lifelink simply causes its controller to gain that much life, as part of its effects. This happens at the same time the damage is dealt, before anything can happen. As a result of this change, lifelink is no longer cumulative in multiples, and a number of cards that had been given errata to have the old triggered ability version of lifelink were de-errata'd so they wouldn't be functionally altered by this change.
Deathtouch - Reversal! The way that the keyword deathtouch works has changed. Rather than being a triggered ability that triggered on damage being dealt, the rules of the game now simply watch for creatures being dealt damage by something that has deathtouch. If a creature is dealt damage by something with deathtouch, that creature is destroyed as a state-based action before any player can do anything. For this reason, a creature no longer requires being regenerated multiple times to save it from multiple instances of deathtouch or from the damage itself; one regeneration covers it all. In combat, any nonzero amount of damage being assigned from something with deathtouch is considered lethal.
Token Ownership - Reversal! The owner of a token used to be the controller of the effect that created it; this is no longer the case. The owner of a token is now the player under whose control the token entered the battlefield.
Outside the Game - Reversal! A card is outside the game if it's not in any of the game's zones. This is a bit of a change for cards like the Wishes that fetched cards from outside the game. Previously they could fetch cards in the exile zone as well as those in your sideboard (or your collection, for casual play), but they can no longer do that.
New Keyword Magic 2010 introduced the keyword Intimidate. For more information on Intimidate, see the Keyword FAQ.
Intimidate is basically a remake of the ability Fear, only without the built-in reference to black. A creature with intimidate can only be blocked by artifact creatures and/or creatures that share at least one color with it. Intimidate was created to replace Fear; while old cards that used Fear won't be issued errata, no new cards with Fear will be printed. Instead, those cards will have Intimidate.
Layers The old 'catchall' Layer 5 (in which everything not already applied besided P/T-modifying effects was applied) has been split into two layers: the first for effects which change colors and the second for effects which add or remove abilities. So now effects which change color will always apply before effects which add or remove abilities.
In addition, effects from things which set P/T to a specific value are now always applied before other modification effects, such as counters, Giant Growth , Glorious Anthem , and so on.
Floating Mana If a player spends mana or passes priority while still having some mana remaining in his or her mana pool, that player must state what mana is still there.
Damage There's a new section on Damage in the Comprehensive Rules explaining how to resolve damage being dealt. First, you apply damage prevention/redirection effects, then the damage is transformed into its results, as modified by replacement effects that care about those results, and then the damage is 'dealt' and the results happen.
Shortcuts The section that used to talk about how to handle 'infinite' loops has been expanded and clarified into a section on shortcuts in general and how to go about them. This introduces a few changes, but nothing you would likely have ever heard of.
Bands with Other and Phasing The way these two keyword mechanics work have changed. The former essentially had its original functionality thrown out the door and replaced with vastly more intuitive functionality, and the latter still functions much the same, but how it goes about it was changed entirely. For more about how each of these abilities work now, see their respective entries in the Keyword FAQ.
Imprint and Substance These two used to be keyword abilities; they are no longer so. Imprint has been turned into an ability word, while Substance has been removed entirely. If you have never heard of substance and don't know what it does, don't sweat it, because it's not important. It didn't actually do anything and doesn't affect you.
APNAP Order If something is being done in APNAP order, and a player who's already been handled is given a new choice to make, that player makes that choice next. APNAP order is restarted for the remaining choices. If you don't know what APNAP order means, just ignore this because you'll likely never see it happen.
First/Double Strike Loophole A small loophole in the rules for first strike allowed a weird interaction; the loophole has been eliminated.
Clarifications
The section on winning and losing the game now explicitly states that a loss may be issued by a judge in a tournament or that an effect may cause the game to end in a draw; this was already mentioned elsewhere, but now it's where it belongs.
The rules on X have been clarified to make it clear that if X is in a card's mana cost, and you're not casting it without paying its mana cost or any alternate cost that replaces X, X has to be 0, even if X is present in some other mandatory additional cost.
The section that talked about *'s within a creature's power and toughness now properly covers creatures like Primal Plasma in addition to those like Maro .
If a spell or ability has begun resolving, it will finish resolving even if it leaves the stack somehow during that process.
A number of terms that existed only in the glossary have been moved into the CompRules proper.
A number of existing terms were added to the section on keyword actions.
The section on state-based actions received a few clarifications and was rearranged so they were listed in a more logical order.
The copy rules received a minor clarification that to fix an oddity that only complete rules-goobers would ever have thought or heard of. (Guilty.)
The multiplayer rules received a bunch of clarifications.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
Changes For:Planechase / Masters Edition III Previous Set:Magic 2010
Planechase - NEW! The release of the Planechase decks introduced the concept of Planechase, a new casual variant officially supported by Wizards of the Coast. A lot of rules were tweaked to support the addition of Planechase. For a full explanation of this variant, see this article.
Drawing the Game and Range of Influence A slight addition to the rules covers what happens if an effect attempts to end a multiplayer game in a draw while the Limited Range of Influence option is being used; everyone within Range of Influence draws, while everyone else continues to play, and may win or lose as normal.
New SBA A new state-based action was added exclusively to handle Rasputin Dreamweaver ; if he has too many counters on him, they are removed.
Clarifications
A bunch of rules that were overlooked, left incomplete, or improperly updated during the M10 update were corrected.
The rules on fortifications were tweaked, since if taken literally they sounded kind of weird.
The rules about improper attachments have been expanded to cover things they didn't properly cover before
A few obsolete rules were removed, and new reminder rules added in.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
Changes For:Zendikar Previous Set:Planechase / Masters Edition III
Vanguard The Casual Variants section of the rules has been expanded to cover Vanguard, both the old oversided paper card version and the Magic Online version based around avatars.
Commander (Elder Dragon Highlander) The rules have also been expanded to cover Commander (formerly known as Elder Dragon Highlander or EDH), the popular casual multiplayer variant which has been showing up all over the place thanks to strong support amongst players, especially Judges. The full rules for Commander can be found here. Note that the addition of Commander rules into the Comprehensive Rules doesn't mean that Wizards is taking responsibility for the format's rules--that's still being handled by the same outside group of people it previously was. It's just being incorporated for ease of use, and will be following along with whatever they decide.
Loyalty Abilities A new section has been added to cover 'loyalty abilities', which are activated abilities with loyalty symbols in their costs. (The ones you see on planeswalkers.) Previously, these abilities were limited to one per turn any time you could cast a sorcery simply by virtue of being on a planeswalker card. This meant that if you could find some way to transfer the ability to a card which wasn't a planeswalker (and there were ways), you could use them as much as you liked without limitation. This was Really Weird, so this section was created. Now, the abilities are limited based on the fact that they include loyalty symbols in their costs, so the limitations of only-one-per-turn and only-any-time-you-could-cast-a-sorcery apply no matter what permanent you manage to sneak them onto. In addition, this cleans up some messy corner cases for planeswalkers.
Subtypes The list of spell types and creature types have been updated. For the full current listing of spell types and creature types, see this post.
'Must target' Thanks to the de-errata-ing of the Flagbearers, a rule was added to cover effects that state that things 'must' target something. (Basically, you must obey as many such effects as possible without violating any effects which say you can't target something.)
Clarifications
The rules for priority included a minor error in stating that players could do things only if they had priority, which isn't quite true--they can also do them when the game instructs them to do so.
Rules were added to cover the new terminology for Kicker used in Zendikar.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
Keyword Abilities Worldwake introduced...well, not quite a new keyword, but a tweak on an old one: Multikicker. For more information, see the Kicker entry in the Keyword FAQ
Multikicker is a variant of Kicker that works pretty much exactly the same way, but instead of only being able to pay the kicker cost once, you can pay the kicker cost as many times as you want to get a scaling effect based on how many times you did so.
Subtypes The lists of creature types and plane types have been expanded. For full lists of existing subtypes, see this post.
Unverifiability Library of Leng can cause unverifiability issues when something is asking about the characteristics of the card being discarded. (It's impossible for the opponent to verify what the characteristics are, since the card is moving from one hidden zone to another.) An addendum to the rules has been added so that if a card is being discarded to a hidden zone, its characteristics are considered undefined.
Subgames The rules for subgames have been modified to properly handle certain alternate formats that use the command zone. (Such as EDH or Planechase.) Cards in the command zone migrate down to the subgame, and then migrate back when the subgame ends.
Clarifications A few small clarifications were made to the rules with this update; these clarifications cause no functional changes, but you may wish to be aware of them anyway.
The rules for winning the game in multiplayer games have received some slight changes, both to cover some accidental omissions and to properly handle new cards; this didn't change how they interacted with anything that already existed.
A number of terms which were previously ill-defined within the rules (or not defined at all) were added to the rulebook.
The rules outlining what a spell or ability can or cannot do to something that's an illegal target have been clarified, since taken literally they would have made some weird corner cases. This merely incorporated existing rulings into the rules.
A set of rules for shuffling have been added to the CompRules as a compilation of existing rulings on the subject.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
Changes For:Rise of the Eldrazi Previous Set:Worldwake
Levelers Rise of the Eldrazi introduced a new kind of card, known as 'levelers', with a unique new striated text box. (You can see an example on Transcendent Master .) The levelers' level up ability allows you to put level counters on them, and as they gain levels they'll become bigger, badder, and ever more dangerous.
A leveler's level is defined as the number of level counters on them (so they start out at level 0), and each striation in the text box describes the abilities (and, for creatures, P/T) the card will have as long as it has the appropriate number of level counters on it. Student of Warfare , for example, is a 1/1 at level 0, but when she becomes level 2 she turns into a 3/3 with first strike, and at level 7 she pumps up again and becomes a 4/4 with double strike instead!
New Keywords Also introduced were a massive four new keywords: Annihilator, Level up, Rebound, and Totem armor. For more information on what each of them does, see their entries in the Keyword FAQ.
Annihilator is an ability that makes things even harder for your opponent when you attack, even if your creature get blocked. When a creature with Annihilator attacks, the defending player is forced to sacrifice permanents equal to the annihilator number (written as 'Annihilator X')--this number could be as low as one, forcing them to sacrifice just a single permanent, or a high as six on some creatures. Even better, these permanents must be sacrificed before blockers can be declared, so your opponent can't block and then sacrifice his blockers to protect himself.
Level up is a keyword used on the new 'leveler' cards. Any time you could cast a sorcery, you may pay the level up cost to put a level counter on that permanent, which will allow your cards to become bigger and more dangerous over time.
Rebound is an ability on instants and sorceries that allows you to get twice the bang for your buck--literally! If you cast a spell with rebound from your hand, you exile it after it resolves instead of putting it into your graveyard. Then, at the beginning of your next upkeep, rebound allows you to cast the spell again, from exile, without paying its mana cost! (The card goes to your graveyard normally when it resolves the second time.)
Totem armor is an ability on Auras that allows them to protect the permanent they're attached to, negating the normal two-for-one disadvantage they're vulnerable to. If a permanent with a Totem armor Aura on it would be destroyed, you remove all damage from it and destroy the armor instead! (If there are multiple totem armors present, you choose just one of them to be destroyed.)
Life Totals in Two-Headed Giant The rules for how effects that check or set a player's life total work in the Two-Headed Giant multiplayer variant have been altered. Previously, if an effect wanted to know a player's life total, it woud see it as being equal to half of the team's life total, rounded up--an effect that set a player's life total would take this number, add or subtract the appropriate amount to it, and then apply that change to the team's life total. While it might sound intuitive on the surface, it led to some incredibly weird interactions of the kind that nobody but rules gurus tended to be able to figure out.
So, it's changing. Now, if an effect wants to know your life total, it gets your team's life total. If something wants to set a player's life total to a specific number, it sets the team's life total to that number. (By making that player gain or lose the appropriate amount of life, just as in regular play.) If it would set the life total of more than one player on the team at once, the team chooses one, and only that player is affected, bringing the team's life total to that number.
So:
If your team has 11 life and you cast Beacon of Immortality , you gain 11 life and your team will wind up at 22 life.
If you control Near-Death Experience , you win the game during your upkeep if your team has exactly 1 life.
If your team has 17 life and you want to activate Lurking Evil 's activated ability, you'll have to pay 9 life to do so, leaving your team at 8.
Clarifications A few clarifications were made with this update, mostly consolidating existing rulings into the rules, adding tweaks to properly cover new cards, or modifying things slightly to properly handle things they way they always should have, but which technically wasn't present in the rules. For example:
If you're putting a card into your library "Nth from the top", but there are fewer than N cards in your library, just place it on the bottom.
The rules for dividing cards into piles now explicitly state that a card can only be in one of those piles.
An effect that looks for the 'active player' in a two-headed giant game refers to only one of the active players, whichever one the controller of the effect wishes.
An aura that is going to the graveyard at the same time as the permanent it's attached to can track both itself and the permanent if it wants to.
Cards that are brought into the game from outside it remain in the game until its conclusion.
The rules on cost-modifying abilities were tweaked a bit.
The rules now define the source and controller of a delayed trigger created by a replacement effect.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
Changes For:Archenemy Previous Set:Rise of the Eldrazi
Archenemy - NEW! The Archenemy decks introduced the Archenemy variant, a casual variant officially supported by Wizards of the Coast. A number of rules were tweaked or otherwise modified to add the new variant to the rules. For a full explanation of the rules of Archenemy, see this article.
Shared Turns Previously, the concept of sharing turns was exclusive to Two-Headed Giant. With the release of Archenemy, the rules for that are being expanded into a full-blown play option which is used by both 2HG and Archenemy, and which can be used by other team games if desired. This doesn't really change very much.
Drawing Cards in 2HG Previously, if both players on a two-headed giant team would draw cards at the same time, the primary player drew them first, then the secondary player. This is being changed; now, players on the team draw the cards in whichever order they wish, though each player still has to draw all of his or her cards at once--no alternating between teammates.
Attacking creature / Defending player The rules for determining who the 'defending player' is, especially in a multiplayer game were altered slightly to account for the possibility that a creature could be removed from combat before something that cared what it was attacking resolved.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
Deathtouch - Reversal Deathtouch's functionality has changed slightly. During the M10 update, creatures with deathtouch were made exempt from damage assignment orders in combat so that it was possible to assign just 1 damage to each blocker, without worrying about the creatures' toughness. This is no longer the case. Instead, any (nonzero) amount of damage being assigned by a creature with deathtouch is now considered to be 'lethal damage' for the purposes of assigning damage in combat. This means that while you do have to abide by the damage assignment order you chose, even just a single point is lethal, so you can still assign 1 to each of the blockers to kill them all. (Assuming your creature has enough power.)
This also has the side effect of boosting deathtouch's power when combined with trample. Since even 1 damage is lethal, you can assign just 1 to each of the blockers, and then assign all the rest to the defending player.
Emblems This update introduced the concept of Emblems, which are game objects that simply hang out in the command zone doing whatever their ability says they do. They don't have colors, names, card types, or anything else except their ability. Their introduction is pretty much solely to help alleviate certain weird rules problems with certain kinds of effects that you likely don't need to worry about.
Creature Types The list of legal creature types has been changed. For a full list of currently existing creature types, see this post.
Grand Melee A number of rules changes have been made to the Grand Melee format, mostly clearing up problems or omissions with the existing rules. About the only significant thing is that if a player loses the game, the range of influence doesn't change until the end of the turn. This is to prevent silly things like Darksteel Reactor taking out a table of 120 people in one fell swoop because the ability keeps triggering. (Instead, they take out the people next to them, and then draw the game because their Reactor can't stop triggering.)
Really, really small things You will likely never need to know these. Still, if you're bound and determined to read about them, here they are:
If your life total is negative, something that asks you to pay half your life total will be asking you to pay a negative amount of life, which is impossible, so you can't do it.
If something would create a token, but something says that a token like that can't enter the battlefield, it isn't created.
An ability that reads "Whenever [a player] gains life..." is treated as though it reads "Whenever a source causes [a player] to gain life..."
If something is giving you the option of making your opponent draw a card, but their library is empty, you can still try it.
If something uses its own name in an ability that changes itself into something else and grants it that same ability, the name still refers to that same thing, even if the name's not the same any more.
If you Desertion a permanent spell that was kicked and put it onto the battlefield, you don't get the kicker effect.
Permanents that phase out during combat are removed from combat.
If a permanent's cumulative upkeep ability triggers, and the permanent is removed before the ability resolves, you no longer have the option of paying the cost anyway.
If a subgame begins in an archenemy deck, the archenemy brings his or her scheme deck along for the ride. (Ongoing schemes are left behind.)
Actions that caused a library to be shuffled can't be reversed if an illegal action happens.
Rules support has been added for Drain Power moving the actual mana it drains between mana pools.
And so people say to me, "How do I know if a word is real?" You know, anyone who's read a children's book knows that love makes things real. If you love a word, use it! That makes it real. Being in the dictionary is an artificial distinction; it doesn't make the word any more real than any other word. If you love a word, it becomes real. --Erin McKean, Redefining the Dictionary
~ 
~ 
~ 
~ 
