Originally posted by José Moreira:
So,
This means playing sloppy compensates?
Instead of doing the spells and ask if they resolve step by step?
In a sense, yes. In another sense, kind of but in a roundabout way. Allow me to explain:
Yes, the end result is that if you play sloppily and do not allow the opponent to respond in places where they have priority, you get a benefit from this handling of the situation. That is fact and is undeniable, and “encourages”, so to speak, sloppy play. However, you're asking the wrong question.
The question you should be asking is, is the game state reparable? If the game state is reparable, you should repair it, and if not, then not. Note that in this definition of “reparable” I am including intangibles such as information transfer in addition to the normal reparable features of the game (with the exception of the information transfer which occurred as part of the game action which prompted the GRV; as far as I'm concerned, part of the penalty for making a GRV such as this is the associated information transfer by the player who made the error). So, to run down the examples:
Player taps Llanowar Elves for mana, taps 4 other lands, casts Bring to Light. Is the game state reparable? Since these are all mana abilities, the opponent did not have priority at any point in this sequence to make a play. Therefore, no information was transferred, aside from the GRV-related information. In addition, nothing else irreparable occurred, so we can rewind.
In the case of the Arbor Elf tapping “for mana” (i.e. shortcutting through it as though it were a mana ability), the opponent technically had priority, but was never prompted. It is reasonable to state (although this is a “you had to be there” situation, so the logic is a bit less tight) that the actions occurred quickly enough that the opponent had no time to respond until the Bring to Light was announced and the GRV occurred. Therefore no information was transferred except the GRV-related information. Again, we can rewind.
In the case of “Arbor Elf, *pause*, untap my land, cast Bring to Light”, the pause indicates that there was a pass of priority. The other player had priority and chose not to use it. This is a transfer of information, that either a) the opponent had a play and chose not to make one, or b) the opponent had no play to make. This is information gained by the player committing the GRV, and is thus not reparable. This is also known as “fishing”, for those who might be familiar with that term, and we do not rewind fishing (for those unfamiliar, “fishing” is when you make a play, let the opponent respond, and then say “oops, I made a mistake let me change my action” when/if they choose not to respond). The “+1 Xenagos, *pause*…” situation is similar, it's also fishing.
Addendum to the above: I would not consider this situation “fishing” if the opponent was visibly F6'd, meaning that a) there is no spell legal in the format he could cast off his available mana, and b) there was no ability he could activate based on his permanents in play. If these cases are both true, then there was no information transfer, because the opponent could not respond due to the constraints of the format, rather than the constraints of the information available. In modern Magic, the former tends to be reasonably easy to determine, as in most cases it derives into whether or not the opponent has mana untapped: If they do, it's false, if they don't, it's true. Exceptions are formats with free spells, which all the older formats have (and hence this is always false and I would never rewind), and when WotC prints a free mechanic in Standard it's usually pretty talked about and hard to miss. The latter is just looking at the board state and reading the cards.
In the case of cracking a fetchland, the deck has been randomized and a card has been removed. We cannot un-randomize the deck, and therefore the game state is not reparable, even if the deck was fully random before the fetch (this last part is mainly for ruling consistency)
One thing I would do in all situations, though, would be to allow the player to untap their lands that they used to cast Bring to Light, regardless of their sequencing. If they said “Tap 4 lands, Xenagos +1, *pause* Bring to Light”, the end result would be those 4 lands untapped and the Xenagos being +1'd. It doesn't make sense to me to penalize the player for tapping their lands first, when if they'd just done the operations in the other order they wouldn't be penalized. Feels too much like
Pro Tour Riot territory for me.
Edited Lyle Waldman (Sept. 26, 2016 03:51:20 PM)