Oath of the Gatewatch Update Bulletin—Comprehensive Rule Changes

Posted in Feature on January 29, 2016

By Matt Tabak

Senior editor. Game designer. Writer. Bon vivant. Matt wears many hats inside Magic R&D, but they're hard to see as he's so tall.

What are the Comprehensive Rules?

Magic is complicated. No, really. When you have more than 14,000 interchangeable game pieces, you get some freaky interactions. The Comprehensive Rules cover everything the game has ever come up with, from basic game play structure, to every keyword ever, to entire pages dedicated to single bizarre cards (hello, Karn Liberated!). The Comprehensive Rules are, well, comprehensive…but they're also obtuse, unfriendly, and looooong. They're not intended to be a player resource—they're a judge resource, a rules guru resource, and a place to store definitive answers. In fact, I honestly recommend never reading them.

For a much friendlier rulebook that is intended to be a player resource, check out the Rules Page and download the Basic Rulebook (4.37 MB PDF). It doesn't have sections about phasing or subgames…but you'll never miss them.

103.4e and 903.8

This rule covered the mulligan procedure in Commander games. In the Commander (2015 Edition) update, we removed the scry that was accidentally added to the basic mulligan rules earlier last year. Originally, the scry wasn't supposed to be there. So I fixed that by trimming 103.4e and 908.3.

But then the committee came to a decision about mulligans, and 103.4e was removed completely for the Oath of the Gatewatch update. The official Commander mulligan rules now match the rules for any other game. If it's a multiplayer game, your first mulligan doesn't cost you a card. After mulligans (in two-player or multiplayer), if you have fewer cards in your hand than your starting hand size, you may scry 1.

106.6 and 106.6a

These rules explicitly explain the interaction between cards that increase the amount of mana produced by a spell or ability and any "riders" on that mana. These riders include effects that state what that mana can be spent on, additional effects that occur when that mana is spent on a particular type of spell or ability, or delayed triggered abilities that trigger when that mana is spent. For example, if you control Mana Reflection and tap Pyromancer's Goggles, a separate delayed triggered ability will be tied to each of the two red mana produced. If you spend one of that mana to cast a sorcery, the appropriate ability will trigger and copy that spell. Then, later in the turn you could spend the other mana to cast an instant, and it too will be copied. This is one of those cases where intent was pretty clear and rulings supported it, but it's better just to have everything spelled out.

106.10 (new)

A rule to handle the case where mana represented by a generic mana symbol is added to your mana pool, just on the off chance you're playing with Elemental Resonance.

107.4 and 107.4c

{C} joins the list of symbols.


This rule explains how we use the term "card" on, erm, cards. For the most part, when we say "card," we mean cards not on the battlefield. But when we're talking about cards moving to the graveyard "from anywhere," "card" becomes a catch-all term that could include cards on the battlefield. We usually call those "nontoken permanents." But, in the interest of giving cards such as Wheel of Sun and Moon attractive templates, this niche use of "card" is acceptable. I tweaked the rule to support this usage.


This rule explains that effects that reduce a cost by an amount of generic mana (such as "Creature spells you cast cost {1} less to cast") affect only the generic mana component of that cost. They don't affect any colored or colorless mana requirements. That is, if Kozilek, the Great Distortion somehow costs {9} less to cast (and really, bravo), you still pay {C}{C}.

117.7d (new)

This new rule covers the case where a cost is reduced by an amount of colorless mana that exceeds its colorless mana component. This is currently impossible, but it mirrors a similar rule with respect to colored mana reductions. (To be fair, even that rule only comes up in one strange case: Khalni Hydra plus something that makes it cost more to cast plus nine or more green creatures. Well, it also comes up when I explain to my family what I do for a living.)


A very small tweak to this rule, which explains how to pay a mana cost, to include the possibility that you could need colorless mana. Imagine such a thing!


Cohort is added to the list of ability words.


I tweaked the description of what a modal spell or ability is to include all the wondrous ways in which we use them now that bullet points are here.

700.2d (new)

Now that the Commander (2015 Edition) Confluences exist, we needed a rule to state that if you choose a mode more than once, you handle the targeting requirements for each mode separately. That is, Verdant Confluence's first mode can target a different creature for each time you chose that mode, or it could target the same creature each time.

701.32 (new)

Support rules!

702.115 and subrules (new)

Myriad new rules to handle the new keyword myriad.


The fact that a phased-out permanent is removed from combat wasn't mentioned in the phasing rules. That was weird, so I added a mention there.


New surge rules, brought to you by my favorite citrus soda, Diet Mountain Dew. It's the only diet with Dew!


This restatement of the mulligan rule for multiplayer games was a little specific about what happens on the first mulligan, saying that you draw seven cards instead of six cards. While true in the vast majority of cases, it wasn't true in all of them, so the language was relaxed a bit.


Known as "Rule 4" on MTGCommander.net, this rule stated that if you tried to produce mana outside of your commander's color identity, you got colorless mana instead. That rule is no more. Now, if I'm playing a blue Commander deck and I gain control of your Forest, I can tap it for {G}.


Entry changes: generic mana, modal, suspend (a minor editing tweak)

New entries: myriad, support, surge


Oracle Changes

Comprehensive Rules

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