So I've been looking into Urborg, Tomb of Yawgmoth and found this errata:
7/18/2014
If Urborg loses its abilities (for example, if it becomes a creature and then Turn to Frog targets it), all lands on the battlefield, including Urborg, will still be Swamps, but Urborg won’t have the ability “Each land is a Swamp in addition to its other land types.” Urborg also won’t be able to tap to produce , but other lands (including those that enter the battlefield later in the turn) will. The way continuous effects work, Urborg’s type-changing ability is applied before the effect that removes both the type-changing ability and its own mana ability.
The scenarios in question are these:
1-Urborg, Tomb of Yawgmoth and Conversion are on the battlefield. I use Magical Hack on 'Tomb to change "swamp" into "mountain".
Hypothesis: 'Tomb is a plains, and all other lands are mountains in addition to their original types.
2-Urborg, Tomb of Yawgmoth and Conversion are on the battlefield. I Magical Hack on Conversion to change "mountain" into swamp".
Hypothesis: 'Tombs is a plains, all other lands are swamps in addition to their original types.
Magical Hack's effect is a text-changing effect (layer 3 [C.R. 613.1c]), so it applies before Urborg's and Conversion's effects (both of which are in layer 4 [C.R. 613.1d]). Therefore, Magical Hack's effect will apply even if Urborg loses its abilities due to Conversion's effect (which will happen in both cases [C.R. 305.7, 305.6]) (the rules that can change how effects are ordered apply only "within a layer or sublayer" [C.R. 613.6, 613.7]).
In the first case, the relevant effects read "Each land is a Mountain in addition..." and "All Mountains are Plains". In the second case, the relevant effects read "Each land is a Swamp in addition..." and "All Swamps are Plains". In both cases, Conversion's effect depends on Urborg's since both effects are in layer 4 and the latter changes what lands the former affects (C.R. 613.7a), (EDIT [after comment 6]: but not vice versa, since applying the former first doesn't "change the text or existence of" the latter or what it applies to)and the latter is not dependent on the former within the meaning of C.R. 613.7a, including because applying the former first doesn't "change the text or existence of" the latter or what it applies to, so the latter is applied before the former (C.R. 613.7b-c), and all lands will be Plains (and no other land types) in either case and generally won't have any abilities other than "T: Add W" (C.R. 305.7, 305.6). EDIT: In both cases, applying Urborg's effect first would change what lands Conversion's effect applies to (within the meaning of C.R. 613.7a).
EDIT: Struck out some parts of this post after comment 5 was posted, and reinstated them after comment 6 after I was shown to be originally correct. The important thing to keep in mind here is that C.R. 613.7 applies only if one of the effects is dependent on the other but the latter is not dependent on the former.
EDIT (Aug. 5): Clarification; added rule citation.
EDIT (Dec. 13, 2018): Correctness edit.
EDIT (Apr. 6, 2019): Add rule citations; clarification; correctness edit.
So I've been looking into Urborg, Tomb of Yawgmoth and found this errata:
7/18/2014
If Urborg loses its abilities (for example, if it becomes a creature and then Turn to Frog targets it), all lands on the battlefield, including Urborg, will still be Swamps, but Urborg won’t have the ability “Each land is a Swamp in addition to its other land types.” Urborg also won’t be able to tap to produce , but other lands (including those that enter the battlefield later in the turn) will. The way continuous effects work, Urborg’s type-changing ability is applied before the effect that removes both the type-changing ability and its own mana ability.
The scenarios in question are these:
1-Urborg, Tomb of Yawgmoth and Conversion are on the battlefield. I use Magical Hack on 'Tomb to change "swamp" into "mountain".
Hypothesis: 'Tomb is a plains, and all other lands are mountains in addition to their original types.
No, all lands are plains. This is a case of dependency: because applying Urborg's effect first changes what Conversion applies to, we apply Urborg first, no matter the order of entrance of the two. It doesn't matter that Urborg loses its ability, because it already applied at that point. The ruling you quoted is for the interaction of Urborg's type-changing effect (layer 4) with ability-removing effects (layer 6). Conversion VS Urborg is layer 4 vs layer 4, so the dependency system is used, see rule 613.7.
2-Urborg, Tomb of Yawgmoth and Conversion are on the battlefield. I Magical Hack on Conversion to change "mountain" into swamp".
Hypothesis: 'Tombs is a plains, all other lands are swamps in addition to their original types.
Agian, all lands are plains. It's pretty much the same as in 1-, you make it so Conversion is applicable to all lands because of Urborg, so we apply Urborg first and Conversion applies to all lands.
Private Mod Note
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Rollback Post to RevisionRollBack
I'm a former judge (lapsed), who keeps up to date on rules and policy. Keep in mind that judges' answers aren't necessarily more valid than those of people who aren't judges; what matters is we can quote the rules to back up our answers. When in doubt, ask for such quotes.
Actually this is going to be determined by timestamp. It's true that in both cases conversion is dependent on Urborg, however the same is true for Urborg. If Urborg is applied first and then conversion, conversion will turn it into a plains which will affect what Urborg would apply to (much the same way Blood Moon does when dealing with that interaction). So what we have here is a dependency loop, which means we revert back to timestamp order.
1) So if Urborg has the earlier timestamp here then it makes all lands into mountains in addition to their other types, then conversion changes everything to plains. On the other hand if conversion has the earlier timestamp we'd apply that first, making all mountains (only those that are mountains before Urborg applies) into plains, and then Urborg applies making all lands mountains in addition to their other types.
2) Same as #1 except for Swamps instead of Mountains.
Actually this is going to be determined by timestamp. It's true that in both cases conversion is dependent on Urborg, however the same is true for Urborg. If Urborg is applied first and then conversion, conversion will turn it into a plains which will affect what Urborg would apply to (much the same way Blood Moon does when dealing with that interaction). So what we have here is a dependency loop, which means we revert back to timestamp order.
On further reflection, you are correct that there is a dependency loop: here, applying Conversion's effect first would "change the text or existence of" Urborg's effect (C.R. 613.7a), so the latter is likewise dependent on the former, therefore a dependency loop exists and timestamp order is used (C.R. 613.7b).
Actually this is going to be determined by timestamp. It's true that in both cases conversion is dependent on Urborg, however the same is true for Urborg. If Urborg is applied first and then conversion, conversion will turn it into a plains which will affect what Urborg would apply to (much the same way Blood Moon does when dealing with that interaction). So what we have here is a dependency loop, which means we revert back to timestamp order.
On further reflection, you are correct that there is a dependency loop: here, applying Conversion's effect first would "change the text or existence of" Urborg's effect (C.R. 613.7a), so the latter is likewise dependent on the former, therefore a dependency loop exists and timestamp order is used (C.R. 613.7b).
I actually don't think this is correct. Before we apply either effect, Urborg does not have any basic land types and so it won't be affected by Conversion. So when we look at what depends on what, we see that applying Conversion first would not have any affect on either the existence of Urborg's ability or which lands Urborg applies to. However, applying Urborg first would have an effect, since it would change which lands Conversion applies to. Therefore we have that Conversion depends on Urborg but not the other way around. The fact that applying Urborg first will then cause it to lose the ability to Conversion is irrelevant, because by that point the effect will have already been applied and removing it would have no impact. Thus Conversion depends on Urborg and we apply Urborg first, followed by Conversion (and all lands are Plains).
There also isn't a dependency loop in the case of Blood Moon, because Urborg doesn't change whether a land is non-basic or not, and thus doesn't affect either the existence of nor the set of lands that Blood Moon applies to. However, Blood Moon changes the existence of Urborg's ability, and thus Urborg depends on Blood Moon but not the other way around. In that case Blood Moon always wins, regardless of timestamps.
I actually don't think this is correct. Before we apply either effect, Urborg does not have any basic land types and so it won't be affected by Conversion. So when we look at what depends on what, we see that applying Conversion first would not have any affect on either the existence of Urborg's ability or which lands Urborg applies to. However, applying Urborg first would have an effect, since it would change which lands Conversion applies to. Therefore we have that Conversion depends on Urborg but not the other way around. The fact that applying Urborg first will then cause it to lose the ability to Conversion is irrelevant, because by that point the effect will have already been applied and removing it would have no impact. Thus Conversion depends on Urborg and we apply Urborg first, followed by Conversion (and all lands are Plains).
There also isn't a dependency loop in the case of Blood Moon, because Urborg doesn't change whether a land is non-basic or not, and thus doesn't affect either the existence of nor the set of lands that Blood Moon applies to. However, Blood Moon changes the existence of Urborg's ability, and thus Urborg depends on Blood Moon but not the other way around. In that case Blood Moon always wins, regardless of timestamps.
You are correct, there is no dependency loop here. We evaluate both effects when they would first apply to see if there are any dependencies, and when thus evaluated there is only one. Sorry for the confusion, so the answer to both questions is the lands will be plains since Urborg will apply first in both cases.
Also I know there isn't a dependency loop for Blood Moon, I was just using it as an example of another dependency.
7/18/2014
If Urborg loses its abilities (for example, if it becomes a creature and then Turn to Frog targets it), all lands on the battlefield, including Urborg, will still be Swamps, but Urborg won’t have the ability “Each land is a Swamp in addition to its other land types.” Urborg also won’t be able to tap to produce , but other lands (including those that enter the battlefield later in the turn) will. The way continuous effects work, Urborg’s type-changing ability is applied before the effect that removes both the type-changing ability and its own mana ability.
The scenarios in question are these:
1-Urborg, Tomb of Yawgmoth and Conversion are on the battlefield. I use Magical Hack on 'Tomb to change "swamp" into "mountain".
Hypothesis: 'Tomb is a plains, and all other lands are mountains in addition to their original types.
2-Urborg, Tomb of Yawgmoth and Conversion are on the battlefield. I Magical Hack on Conversion to change "mountain" into swamp".
Hypothesis: 'Tombs is a plains, all other lands are swamps in addition to their original types.
How wrong am I?
Thank you for your time.
In the first case, the relevant effects read "Each land is a Mountain in addition..." and "All Mountains are Plains". In the second case, the relevant effects read "Each land is a Swamp in addition..." and "All Swamps are Plains". In both cases, Conversion's effect depends on Urborg's since both effects are in layer 4 and the latter changes what lands the former affects (C.R. 613.7a),
(EDIT [after comment 6]: but not vice versa, since applying the former first doesn't "change the text or existence of" the latter or what it applies to)and the latter is not dependent on the former within the meaning of C.R. 613.7a, including because applying the former first doesn't "change the text or existence of" the latter or what it applies to, so the latter is applied before the former (C.R. 613.7b-c), and all lands will be Plains (and no other land types) in either case and generally won't have any abilities other than "T: Add W" (C.R. 305.7, 305.6). EDIT: In both cases, applying Urborg's effect first would change what lands Conversion's effect applies to (within the meaning of C.R. 613.7a).EDIT: Struck out some parts of this post after comment 5 was posted, and reinstated them after comment 6 after I was shown to be originally correct. The important thing to keep in mind here is that C.R. 613.7 applies only if one of the effects is dependent on the other but the latter is not dependent on the former.
EDIT (Aug. 5): Clarification; added rule citation.
EDIT (Dec. 13, 2018): Correctness edit.
EDIT (Apr. 6, 2019): Add rule citations; clarification; correctness edit.
Agian, all lands are plains. It's pretty much the same as in 1-, you make it so Conversion is applicable to all lands because of Urborg, so we apply Urborg first and Conversion applies to all lands.
Actually this is going to be determined by timestamp. It's true that in both cases conversion is dependent on Urborg, however the same is true for Urborg. If Urborg is applied first and then conversion, conversion will turn it into a plains which will affect what Urborg would apply to (much the same way Blood Moon does when dealing with that interaction). So what we have here is a dependency loop, which means we revert back to timestamp order.
1) So if Urborg has the earlier timestamp here then it makes all lands into mountains in addition to their other types, then conversion changes everything to plains. On the other hand if conversion has the earlier timestamp we'd apply that first, making all mountains (only those that are mountains before Urborg applies) into plains, and then Urborg applies making all lands mountains in addition to their other types.
2) Same as #1 except for Swamps instead of Mountains.
On further reflection, you are correct that there is a dependency loop: here, applying Conversion's effect first would "change the text or existence of" Urborg's effect (C.R. 613.7a), so the latter is likewise dependent on the former, therefore a dependency loop exists and timestamp order is used (C.R. 613.7b).I actually don't think this is correct. Before we apply either effect, Urborg does not have any basic land types and so it won't be affected by Conversion. So when we look at what depends on what, we see that applying Conversion first would not have any affect on either the existence of Urborg's ability or which lands Urborg applies to. However, applying Urborg first would have an effect, since it would change which lands Conversion applies to. Therefore we have that Conversion depends on Urborg but not the other way around. The fact that applying Urborg first will then cause it to lose the ability to Conversion is irrelevant, because by that point the effect will have already been applied and removing it would have no impact. Thus Conversion depends on Urborg and we apply Urborg first, followed by Conversion (and all lands are Plains).
There also isn't a dependency loop in the case of Blood Moon, because Urborg doesn't change whether a land is non-basic or not, and thus doesn't affect either the existence of nor the set of lands that Blood Moon applies to. However, Blood Moon changes the existence of Urborg's ability, and thus Urborg depends on Blood Moon but not the other way around. In that case Blood Moon always wins, regardless of timestamps.
You are correct, there is no dependency loop here. We evaluate both effects when they would first apply to see if there are any dependencies, and when thus evaluated there is only one. Sorry for the confusion, so the answer to both questions is the lands will be plains since Urborg will apply first in both cases.
Also I know there isn't a dependency loop for Blood Moon, I was just using it as an example of another dependency.