Cards like Akroma's Memorial that grant abilities as a continuous effect will sometimes end up giving a permanent multiple instances of the same ability. (Such as if you also controlled Akroma, Angel of Wrath.) This causes no problems, as multiple instances of these abilities is redundant.
But how could you word a similar ability that grants a triggered ability like prowess to all creatures, but without giving another instance of it to creatures that have it naturally?
My initial attempt was modeled after Muraganda Petroglyphs: "Creatures you control without prowess have prowess". But now that the creature has prowess, it stops being eligible for getting prowess! Will it work as intended, or is self-dependency a hopeless endeavor?
A self-dependent ability will not retroactively fail to apply. This is because once an effect has applied as part of the layer system, it's impossible for it to "un-apply" itself.
However, "un-applying" an effect is different than the effect simply having no end result. For instance, neither of the following cases are instances where an effect "un-applies" itself:
1) Effect A gives my creature flying, but effect B, which applies later than effect A, causes my creature to lose flying and be unable to gain flying. Effect A has still applied, but the result of the creature having flying isn't there.
2) Effect C causes my creature that was originally red to become blue. Effect D, which applies later than effect C, states that red creatures I control get +1/+1. Effect D doesn't suddenly "un-apply" itself; applying it just has no result (assuming I control no other creatures).
In short, "creatures you control without prowess gain prowess" works fine. The only issue may have to do with timestamps relative to other effects that give prowess.
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How to use card tags (please use them for everybody's sanity)
[c]Lightning Bolt[/c] -> Lightning Bolt
[c=Lightning Bolt]Apple Pie[/c] -> Apple Pie
Vowels-Only Format Minimum deck size: 60 Maximum number of identical cards: 4 Ban list: Cards whose English names begin with a consonant, Unglued and Unhinged cards, cards involving ante, Ancestral Recall
The layer system's rules don't mention that an effect that has applied get "un-applied" just because the criteria for applying the effect are no longer met after the effect's application, so it simply stays applied.
It works fine. Otherwise, cards like Aegis of the Meek wouldn't work. Whether the ability is static or not doesn't matter, because both static abilities and non-static ones use the layer system.
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Rollback Post to RevisionRollBack
How to use card tags (please use them for everybody's sanity)
[c]Lightning Bolt[/c] -> Lightning Bolt
[c=Lightning Bolt]Apple Pie[/c] -> Apple Pie
Vowels-Only Format Minimum deck size: 60 Maximum number of identical cards: 4 Ban list: Cards whose English names begin with a consonant, Unglued and Unhinged cards, cards involving ante, Ancestral Recall
It works fine. Otherwise, cards like Aegis of the Meek wouldn't work.
This isn't a great example, because Aegis of the Meek only cares about whether the creature is 1/1 long enough to check target legality.
But this does work as described here - consider Conversion or Glaciers as proof of this. The continuous effect "All Mountains are Plains" overwrites the land type of all permanents it affects so that they aren't Mountains anymore, but continues to affect them anyway.
Actually, Blood Moon isn't an example of this either since it doesn't add the Basic supertype to anything. A land can be a Mountain (even if it's a Mountain without having other types, e.g. Madblind Mountain) and not be basic.
More or less on-topic: How would this work for cards like Escaped Shapeshifter (which specifies in the errata that it only cares if another creature with a different name has these abilities)? As far as I know, a card which simply reads "This creature has flying as long as another creature you control has flying" wouldn't really work, since if you had two in play they wouldn't have flying until one gained flying, in which case they would always have flying because the other one does.
I ask because I, like everyone, really want WotC to just print a creature with "This creature has all keyword abilities of other creatures on the battlefield" or something to that effect instead of the Soulflayers and Odric, Lunarch Marshals that we keep getting. Is that something they don't print only for being unintuitive, or does it actually not work as-intended?
More or less on-topic: How would this work for cards like Escaped Shapeshifter (which specifies in the errata that it only cares if another creature with a different name has these abilities)? As far as I know, a card which simply reads "This creature has flying as long as another creature you control has flying" wouldn't really work, since if you had two in play they wouldn't have flying until one gained flying, in which case they would always have flying because the other one does.
Are you still referring to the originally proposed "Muraganda Prowessglyphs" card idea? This is actually pretty straightforward.
Assuming that the card added flying: If the only creature affected is Escaped Shapeshifter, it will have flying as long as the Glyphs are around. If there are other creatures that don't natively have flying, Shapeshifter will have flying - I think this could create a dependency where Glyphs has to apply first because it changes whether Shapeshifter's effect applies, but since they're both trying to add flying it doesn't make a big difference. Ending the Glyphs effect would cause Shapeshifter to lose flying since both the effect trying to give it flying directly and its own effect that looks at the other creature won't see flying anymore. If there's another creature that natively has flying, Shapeshifter will just use that - there's another dependency that forces Shapeshifter's effect to apply before Glyph's.
I ask because I, like everyone, really want WotC to just print a creature with "This creature has all keyword abilities of other creatures on the battlefield" or something to that effect instead of the Soulflayers and Odric, Lunarch Marshals that we keep getting. Is that something they don't print only for being unintuitive, or does it actually not work as-intended?
There would have to be a rules update that defines what it means for something to have all keyword abilities, because some of them have costs (Echo), variables (Rampage, Bushido), or other related defining information (Champion). The logical solution is to have it copy the values from the thing it's inheriting the ability from, so the creature would have, say, echo 3WW, bushido 5, and champion a Faerie if you have Karmic Guide, Konda, Lord of Eiganjo, and Mistbind Clique on the field. But the rules don't actually support this at the moment.
There are other keywords that have unintuitive effects that, while not something that breaks how the rules work, would still be problematic. This creature would have Bloodthirst while on the battlefield, but not before, so it wouldn't actually get counters from entering because the game cares about whether it has the ability before it enters. And if the creature inherits Morph and then gets turned face down, it can't unmorph because in its face-down state it doesn't natively have Morph and its ability-inheriting ability isn't active.
Also, it's not clear how "this creature has all keyword abilities" would play with abilities where multiple instances are cumulative. If multiple creatures have Extort, does this creature have that many instances of Extort or just one? Same with Bushido again.
And really, do you want your creature to have Defender, Shadow, and Fading?
There are other keywords that have unintuitive effects that, while not something that breaks how the rules work, would still be problematic. This creature would have Bloodthirst while on the battlefield, but not before, so it wouldn't actually get counters from entering because the game cares about whether it has the ability before it enters. And if the creature inherits Morph and then gets turned face down, it can't unmorph because in its face-down state it doesn't natively have Morph and its ability-inheriting ability isn't active.
Also, it's not clear how "this creature has all keyword abilities" would play with abilities where multiple instances are cumulative. If multiple creatures have Extort, does this creature have that many instances of Extort or just one? Same with Bushido again.
And really, do you want your creature to have Defender, Shadow, and Fading?
I seem to recall hearing that the weirdest ones are things like changeling and devoid that change a permanent's characteristics, since layering applies those before it applies the abilities which grant them to you (i.e. you would have devoid but not actually be colorless).
But how could you word a similar ability that grants a triggered ability like prowess to all creatures, but without giving another instance of it to creatures that have it naturally?
My initial attempt was modeled after Muraganda Petroglyphs: "Creatures you control without prowess have prowess". But now that the creature has prowess, it stops being eligible for getting prowess! Will it work as intended, or is self-dependency a hopeless endeavor?
However, "un-applying" an effect is different than the effect simply having no end result. For instance, neither of the following cases are instances where an effect "un-applies" itself:
1) Effect A gives my creature flying, but effect B, which applies later than effect A, causes my creature to lose flying and be unable to gain flying. Effect A has still applied, but the result of the creature having flying isn't there.
2) Effect C causes my creature that was originally red to become blue. Effect D, which applies later than effect C, states that red creatures I control get +1/+1. Effect D doesn't suddenly "un-apply" itself; applying it just has no result (assuming I control no other creatures).
In short, "creatures you control without prowess gain prowess" works fine. The only issue may have to do with timestamps relative to other effects that give prowess.
[c]Lightning Bolt[/c] -> Lightning Bolt
[c=Lightning Bolt]Apple Pie[/c] -> Apple Pie
Vowels-Only Format
Minimum deck size: 60
Maximum number of identical cards: 4
Ban list: Cards whose English names begin with a consonant, Unglued and Unhinged cards, cards involving ante, Ancestral Recall
With that in mind, do you think there's currently support for a static ability like this in the rules?
EDIT: As mentioned, and as worded in OP, it's a continuous effect of a static ability on a permanent, not the effect of a spell or activated ability.
It works fine. Otherwise, cards like Aegis of the Meek wouldn't work. Whether the ability is static or not doesn't matter, because both static abilities and non-static ones use the layer system.
[c]Lightning Bolt[/c] -> Lightning Bolt
[c=Lightning Bolt]Apple Pie[/c] -> Apple Pie
Vowels-Only Format
Minimum deck size: 60
Maximum number of identical cards: 4
Ban list: Cards whose English names begin with a consonant, Unglued and Unhinged cards, cards involving ante, Ancestral Recall
But this does work as described here - consider Conversion or Glaciers as proof of this. The continuous effect "All Mountains are Plains" overwrites the land type of all permanents it affects so that they aren't Mountains anymore, but continues to affect them anyway.
Thanks.
I ask because I, like everyone, really want WotC to just print a creature with "This creature has all keyword abilities of other creatures on the battlefield" or something to that effect instead of the Soulflayers and Odric, Lunarch Marshals that we keep getting. Is that something they don't print only for being unintuitive, or does it actually not work as-intended?
- Rabid Wombat
Assuming that the card added flying: If the only creature affected is Escaped Shapeshifter, it will have flying as long as the Glyphs are around. If there are other creatures that don't natively have flying, Shapeshifter will have flying - I think this could create a dependency where Glyphs has to apply first because it changes whether Shapeshifter's effect applies, but since they're both trying to add flying it doesn't make a big difference. Ending the Glyphs effect would cause Shapeshifter to lose flying since both the effect trying to give it flying directly and its own effect that looks at the other creature won't see flying anymore. If there's another creature that natively has flying, Shapeshifter will just use that - there's another dependency that forces Shapeshifter's effect to apply before Glyph's.
There would have to be a rules update that defines what it means for something to have all keyword abilities, because some of them have costs (Echo), variables (Rampage, Bushido), or other related defining information (Champion). The logical solution is to have it copy the values from the thing it's inheriting the ability from, so the creature would have, say, echo 3WW, bushido 5, and champion a Faerie if you have Karmic Guide, Konda, Lord of Eiganjo, and Mistbind Clique on the field. But the rules don't actually support this at the moment.
There are other keywords that have unintuitive effects that, while not something that breaks how the rules work, would still be problematic. This creature would have Bloodthirst while on the battlefield, but not before, so it wouldn't actually get counters from entering because the game cares about whether it has the ability before it enters. And if the creature inherits Morph and then gets turned face down, it can't unmorph because in its face-down state it doesn't natively have Morph and its ability-inheriting ability isn't active.
Also, it's not clear how "this creature has all keyword abilities" would play with abilities where multiple instances are cumulative. If multiple creatures have Extort, does this creature have that many instances of Extort or just one? Same with Bushido again.
And really, do you want your creature to have Defender, Shadow, and Fading?
I seem to recall hearing that the weirdest ones are things like changeling and devoid that change a permanent's characteristics, since layering applies those before it applies the abilities which grant them to you (i.e. you would have devoid but not actually be colorless).
- Rabid Wombat