Corpsejack Menace

if it dies with undying, does it return with one or two +1/+1 counters?

I suspect it's only one because the replacement effect wasn't active prior to the event (614.4) of Corpsejack Menace entering the field.

However, triggers see the placement of the counters as it enters (121.6) so I was wondering if the replacement effect would likewise?

Does 614.12 play any role here?
Would the fact that CM is entering the field with a counter make CM's own replacement effect relevant to its own entry into the field?

Your assumption is right, Corpsejack Menace's replacement effect is not applicable while it is entering the battlefield, so it returns with just one +1/+1 counter.

CR 614.12 does play a role, because Undying creates a replacement effect that modifies how a permanent enters the battlefield. However, the relevant parts of the rule are:

To determine which replacement effects apply and how they apply, check the characteristics of the permanent as it would exist on the battlefield,

– you notice that Corpsejack Menace would indeed be a creature you control and have a static ability that creates a replacement effect for counters being put on your creatures –

taking into account replacement effects that have already modified how it enters the battlefield (see rule 616.1)

– this is the +1/+1 counter from Undying –

(…) and continuous effects from the permanent's own static abilities (…)

– too bad, the static ability of Corpsejack Menace doesn't create a continuous effect. CR 614.12 doesn't mention that replacement effects from the permanent's static abilities are taken into account (except for those that also modified how it entered the battlefield, of course). So they are not applied to the replacement effects that modify how this permanent enters the battlefield.

Edit: I was unaware that replacement effects are a subset of continuous effects, thus the conclusion in my last paragraph does not hold. Sorry. I suggest someone with more “officiality” should answer the initial question.

Edited Mario Haßler (Jan. 28, 2013 10:22:57 AM)

So how does this compare with, say, Fathom Mage's second ability. According to the FAQ, if Fathom Mage enters the battlefield with a +1/+1 counter, her ability will trigger. Why does that work that way, while Corpsejack Menace doesn't. Is it just because hers is a trigger rather than rather replacement effect?

Right. CR 603.6d states that “objects that exist immediately after an event are checked to see if the event matched any trigger conditions.” That's why a creature with an enters-the-battlefield ability will trigger its own ability, although the creature only had that ability right after it changed zones and its own appearance from spell to permanent (see e. g. Harmonic Sliver). For the same reason, Fathom Mage's ability triggers when that creature entered the battlefield with a +1/+1 counter, because the (modified) event matches the trigger condition of the Fathom Mage as it exists on the battlefield (with a little help from CR 121.6).

Sorry, I had to withdraw my first answer due to the reasons given in the “edit” comment I added to that post. I ask some of the officials to please answer the initial question. Furthermore, I'll add two questions because I think they're related to the same rules and they could give more insight in that matter:

Two Master Biomancers enter the battlefield at the same time. Does either one give the +1/+1 counter bonus to the other? If so, how many counters will there be on them?

Will Melira, Sylvok Outcast have a -1/-1 counter when she returns to the battlefield after she gained persist and then died?

“614.12. Some replacement effects modify how a permanent enters the battlefield. (…) To determine which replacement effects apply and how they apply, check the characteristics of the permanent as it would exist on the battlefield, taking into account (…) continuous effects from the permanent’s own static abilities, but ignoring continuous effects from any other source that would affect it.”

So, I would say CM will have 2 counters placed on him.

Corpsejack Menace enters with just one counter. Its ability doesn't work as the menace enters the battlefield; it only works if the menace is already on the battlefield.

Here is the relevant part of the rule.

614.12. Some replacement effects modify how a permanent enters the battlefield. (See rules 614.1c–d.) Such effects may come from the permanent itself if they affect only that permanent (as opposed to a general subset of permanents that includes it). They may also come from other sources. (…)
Example: Orb of Dreams is an artifact that says “Permanents enter the battlefield tapped.” It won’t affect itself, so Orb of Dreams enters the battlefield untapped.

So, for example, Orb of Dreams doesn't cause itself to etb tapped, but Diregraf Ghoul does.

Another example: the ability of Melira, Sylvok Outcast doesn't work as Melira enters the battlefield, but the ability of Tatterkite does work as Tatterkite enters. So Tatterkite can't enter with a counter, but Melira can.

For the same reasons, two Master Biomancers entering at the same time will get no counters and no mutations.

112.6. Abilities of an instant or sorcery spell usually function only while that object is on the stack. Abilities of all other objects usually function only while that object is on the battlefield. The exceptions are as follows:
(…)
112.6g An object’s ability that modifies how that particular object enters the battlefield functions as that object is entering the battlefield. See rule 614.12.

112.6h An object’s ability that states counters can’t be placed on that object functions as that object is entering the battlefield in addition to functioning while that object is on the battlefield.

@Nelson: You seem to overlook that the highlighted part of CR 614.12 is related only to replacement effects that modify how a permanent enters the battlefield. But the examples discussed here are about other kinds of replacement effects that just happen to be applicable (or not) to a modified ETB event: Neither Corpsejack Menace nor Melira, Sylvok Outcast has a replacement effect that modifies how they or another permanent enters the battlefield, so they don't fall under that highlighted part. They may be applicable to the ETB event due to “taking into account (…) continuous effects from the permanent's own static abilities”, though.

I suggest let's wait for an official answer.

Edit: Grr… Master Biomancer acutally has such a replacement effect, of course, but the others don't.

Edited Mario Haßler (Jan. 28, 2013 11:46:05 AM)

Actually, both Corpsejack Menace and Master Biomancer create replacement effects that modify how permanents enter the battlefield. Melira doesn't, but the relevant point is still the same for the three cards: rule 112.6 tells us that neither of their abilities work as the permanents they're on enter the battlefield.

Since we have a request for an Official answer, I'll lock this thread until that can be prepared and posted.

Thanks - Scott Marshall, L5, occasional Official answerer

Corpsejack Menace with undying will return with 1 +1/+1 counter.

Two Master Biomancers entering at the same time will not boost each other.

Melira with persist will come back with a -1/-1 counter.

Nelson has it right here - all these are replacement effects which affect how a set of objects enter the battlefield, so they will not affect how the object carrying them enters the battlefield. They have to exist before the zone change to affect it.

By 614.12, a replacement effect created by an object will affect that object entering the battlefield only if it affects the object specifically, calling it by its name or by “it”. Examples: 1. Abandoned Outpost enters the battlefield tapped. 2. When Oubliette leaves the battlefield, return the exiled card to the battlefield under its owner's control tapped with the noted number and kind of counters on it.

Daniel Kitachewsky
L3, Paris, France
Rules Netrep

While I expected the result, the explanation is puzzling me.

Corpsejack Menace has a replacement effect for counters being put on creatures. Melira, Sylvok Outcast is about counters, too, but I'm not even sure if it is a replacement effect. In any case, they both don't even mention the word “battlefield”, so they neither match CR 614.1c nor 614.1d. But CR 614.12 expressly points to these rules in order to identify “replacement effects (that) modify how a permanent enters the battlefield”.

Without doubt, their replacement effects become applicable when another replacement effect (like undying or persist) modifies how creatures enter the battlefield, so they indeed affect that object or set of objects. But they're not per se replacement effects that modify how a permanent enters the battlefield. Because of this, they don't fall under the first sentence of CR 614.12, and the fact that they affect a set of objects is irrelevant.

David, maybe you can elaborate more on this. I expected you would solve the apparent contradiction between CR 614.4 (“Replacement effects must exist before the appropriate event occurs” – that was my guess for the explanation) and CR 614.12 (“To determine which replacement effects apply and how they apply, (… take into account …) continuous effects from the permanent's own static abilities” – here, after learning that replacement effects are a subset of continuous effect, I wasn't sure anymore).

I understand the cited part of CR 614.12 is necessary to make a replacement effect like “Creatures with flying enter the battlefield tapped” work – you have to check whether the creature has flying as it would exist on the battlefield in order to decide whether the replacement effect has to be applied or not. But the rule doesn't expressly exclude replacement effects, that's why I see a contradiction to CR 614.4.

Technically, persist and undying don't qualify as replacement effects based on the wordings of CR614.1c either.

Also, 112.6g-h surely play a role in the answer.

Edited Todd Bussey (Jan. 29, 2013 02:00:05 PM)

Originally posted by Mario Haßler:

Without doubt, their replacement effects become applicable when another replacement effect (like undying or persist) modifies how creatures enter the battlefield, so they indeed affect that object or set of objects. But they're not per se replacement effects that modify how a permanent enters the battlefield. Because of this, they don't fall under the first sentence of CR 614.12, and the fact that they affect a set of objects is irrelevant.

Since the Replacement-Effects of Corpsejack Menace and Melira, Sylvok Outcast become applicable when another replacement effect modifies the event how a creature enters the battlefield they indeed are also modifying the event how the creature enters the battlefield and therefore are also subject to CR614.12. The fact, that they don't explicitly apply when a permanent enters the battlefield is irrelevant. It only matters that they become applicable to an event that does so.

In fact (as Todd pointed out) a replacement effect, that modifies how an object enters the battlefield doesn't necessary need the wordings stated in CR 614.1c and 1d. As long as an effect applies to an event that modifies how an object enters the battlefield it is subject to CR 614.12.

Originally posted by Mario Haßler:

David, maybe you can elaborate more on this. I expected you would solve the apparent contradiction between CR 614.4 (“Replacement effects must exist before the appropriate event occurs” – that was my guess for the explanation) and CR 614.12 (“To determine which replacement effects apply and how they apply, (… take into account …) continuous effects from the permanent's own static abilities” – here, after learning that replacement effects are a subset of continuous effect, I wasn't sure anymore).

I'm not sure, if I got your point here.
For me, there is no contradiction between CR 614.4 and CR 614.12. Since as of CR 112.6g an objects ability that modifies how itself enters the battlefield works as it enters the battlefield.

OK, you could extend Daniel's answers by “In all cases 614.12 doesn't apply, therefore 614.4 steps in and prevents the abilities from modifiying the event how the creatures enter the battlefield.”

Ui, this is getting bigger and bigger…

Originally posted by Todd Bussey:

Technically, persist and undying don't qualify as replacement effects based on the wordings of CR614.1c either.

Don't know if you meant this funny, but somehow it is funny… I guess the slight difference in how it's written doesn't degrade it to not being a replacement effect.

Also, 112.6g-h surely play a role in the answer.

Don't think so, because those rules are about an object's abilities refering to that object and not to a general set of objects.

Farid Taoubi
Since the Replacement-Effects of Corpsejack Menace and Melira, Sylvok Outcast become applicable when another replacement effect modifies the event how a creature enters the battlefield they indeed are also modifying the event how the creature enters the battlefield and therefore are also subject to CR614.12.

I don't deny that. The question is just how they are subject to it. I'll try to make it clear with a fictitious example of a set of replacement effects:

• If you would gain life, draw that many cards instead.
  
• If a counter would be placed on a permanent you control, gain 1 life instead.
  
• Corpsejack Menace
  
• Young Wolf
  

Except for Undying, I wouldn't call any of these a replacement effect that modifies how a permanent enters the battlefield. Still, when Young Wolf dies and returns, they all become applicable with the result that Young Wolf comes back without a counter and I draw two cards.
As I tried to explain, I see Undying and Persist subject to the first part of CR 614.12 because they (more or less) match CR 614.1c:

614.1c Effects that read “(This permanent) enters the battlefield with . . . ,” “As (this permanent) enters the battlefield . . . ,” or “(This permanent) enters the battlefield as . . . ” are replacement effects.

614.12. Some replacement effects modify how a permanent enters the battlefield. (See rules 614.1c-d.) Such effects may come from the permanent itself if they affect only that permanent (as opposed to a general subset of permanents that includes it). They may also come from other sources.

Corpsejack Menace doesn't fall into that category because it doesn't match CR 614.1c-d (not even approximately). Still its ability is subject to CR 614.12 because of

To determine which replacement effects apply and how they apply, check the characteristics of the permanent as it would exist on the battlefield, taking into account replacement effects that have already modified how it enters the battlefield (see rule 616.1), continuous effects generated by the resolution of spells or abilities that changed the permanent's characteristics on the stack (see rule 400.7a), and continuous effects from the permanent's own static abilities, but ignoring continuous effects from any other source that would affect it.

This part of the rule does not distinguish between the permanent's abilities affecting only this permanent and those affecting a general subset of permanents that includes it. They just say to take into account continuous effects from the permanent's own static abilities.

That leads us to the contradiction, at least how I see it: An undying Corpsejack Menace is subject to the Undying ETB replacement effect that wants to put a +1/+1 counter on it. Since this matches the first part of CR 614.12, we'll go through the “determine” instruction list that tells us we should take into account continuous effects from Corpsejack Menace's static abilities as it would exist on the battlefield. That would mean to apply its replacement effect so that Corpsejack Menace would enter with two +1/+1 counters. But CR 614.4 says don't apply replacement effects that didn't exist before the event, and David's answer also was one +1/+1 counter and not two.

To solve this:

• the first part of CR 614.12 should not only specify ETB replacement effects according to CR 614.1c-d but also other replacement effects that become applicable due to the ETB replacement effects (and then say that they too are only applied if they affect only that permanent); or
  
• the last part of CR 614.12 should instruct us to take into account continuous effects from the permanent's own static abilities only if they affect only that permanent; or
  
• someone should try to open my eyes so that I can see what you can see.
  

Meanwhile thank you all for your efforts so far.