Triggers on creatures entering play somehow

Tilwin90 Posts: 662 Critical Contributor
Because there have been quite a few confusions with objectives and effects caused by creatures "entering the battlefield", being "summoned", being "Created", etc. I decided to reopen Pandora's box here and give my two cents on the rules.

1.1. A creature is cast -> enters the battlefield -> if an identical creature already exists, it reinforces that creature instead of creating a new creature stack (all these trigger)
1.2. A creature is put onto the battlefield (from library, graveyard or exile) -> enters the battlefield -> if an identical creature already exists, it reinforces that creature instead of creating a new creature stack.

Notice that in both these situation, there would be two distinct triggers of entering the battlefield and reinforcing a creature and that occur whether the creature is played from hand or put onto the battlefield from anywhere.

Creature tokens
2. A creature token is created -> enters the battlefield -> if an identical token already exists, it reinforces that token instead of creating a new creature stack .

So all in all we end up with the following relevant triggers:
- player casts a creature card (from hand)
player creates a creature token
creature enters the battlefield (from anywhere)
a creature is reinforced 
(creation of creature stack is not a trigger)

Now this becomes highly relevant if we start discussing replacing, triggered effects and objectives:

a) Triggers - having only these three specific actions would mean that three types of triggered abilities could be employed - either on the cards referencing themselves or other cards responding to these actions:
- Whenever a player casts a creature
- Whenever a player creates a creature token
- Whenever a creature enters the battlefield
- Whenever a creature is reinforced

However, for the sake of simplicity and because the fourth trigger is always preceded by the third (but not the other way around), I am inclined towards using the reinforce trigger scarcely (funny enough right now it is so scarce that I have not found any card that responds to that trigger yet).

Triggers cleanup: We should have no effects triggering when a "creature is summoned" (what does summoning even mean, is it cast or ETB?), when a creature "is played" (which most likely suggests cast) etc.

Naturally any specific conditions can still be bound to these triggers (a "VAMPIRE" creature is cast, a "WHITE creature token" is created, a "creature with power 5 or more" enters the battlefield etc.)

Creature Stealing: Very important that I bring this up. Whenever a creature is stolen, normally it should only change ownership. I am referring here to effects caused by cards such as Exert Influence and In Bolas's Clutches (NOT Etali, Hostage Taker or Mastermind's Acquisition that steal cards and put them into hand). Since those creatures were already onto the battlefield, they shouldn't be counted as "entering the battlefield" once again. I noticed inconsistencies here especially between objectives counting (that do not count them as entering) and triggers on the cards themselves (that do trigger after the steal occurs). 

b) Replacement effects - the mother of all replacement effects here is probably Leader. It could read as "Leader [type] - whenever you would create a [type] creature token, reinforce this creature instead". 
- because the creature token is created before it enters the battlefield, the actual creation of the creature token never occurs
- because the creation of the token never occurred, that token never gets to enter the battlefield either.
- effects triggering as a result of a creature entering the battlefield would not trigger (so no Ajani's Welcome, Path of Discovery, Decoction Module, Vanquisher's Banner or Zendikar Resurgent freebies, but also no penalty from Authority of the Consuls)
- because your leader would be reinforced, any effects triggering as a result of a creature being reinforced would occur (no such cards exist so far)
- regarding competing replacement effects (such as Mistcaller in the case of our Leader), I would initially look at rule 615 in paper magic, which indeed does not help us very much - in the case of competing effects, it is the player that chooses which effect happens.

Competing replacement effects proposal: Since the effects here are automated, personally I would go with a more generic approach and just pick our nice "timestamp" rule - first replacement effect takes priority. In our case, if the current Misty stack was created prior to the Leader stack, then the tokens would end up exiled (sorry). Otherwise, the leader takes priority and gets reinforced. In either case, the subsequent token would not get created.

c) Objectives - I think this is the most painful subject that interests most of us, and is the area of plenty of confusions. Just like with the triggers above, there are so many formulations in terms of objectives. Once again, I would honestly go with the four main categories here (with the last being used sparingly).
- Objectives that require "casting" a creature - they do not count creature tokens or creatures being fetched from the library or reanimated
- Objectives that require "creating" a token - they do not count creature cards
- Objectives that require creatures "entering the battlefield" - they count both creatures and tokens and are probably the most inclusive of all
- Objectives that count the number of times "creatures are reinforced" - more restrictive and tricky than the ETB since it relies on keeping your creature stacks to get them reinforced.

Having these four categories can replace all existing objectives as such.

Suggestion of avoidable objectives:
- Objectives that require X or less creatures entering the battlefield. This would require one to rely exclusively on card steal (if it were properly implemented) and dealing damage with spells.
- Objectives that require high X or more creatures being cast. An example here is the Halloween event which effectively requires one to cast 13 zombies (a completely ridiculous and grindy number). If it were an "enters the battlefield" triggers count, or maybe even counting the number of reinforcements (there are quite a few ways to generate zombie tokens and reinforce them right now) it would be quite interesting actually.

These are my two cents on the topic. I'm sure there are still quite a few rulings aspects I have missed so feel free to jump in on the topic.


  • Mburn7
    Mburn7 Posts: 3,427 Chairperson of the Boards
    This is very complete and seems pretty legit to me (my only real issue would be with your Mistcaller ruling, but like you said there isn't much to go on there no matter what is done)

    @Brigby I assume (hope) the Devs already have some sort of (hopefully simplified and more inclusive) chart like this, but if they don't it would be a good idea to spend a few hours and make it (and then fix the wording and coding in app to reflect it).  I know they are super busy with GRN and the bugs right now, but something like this would go a long way toward making the app functional 
  • Tilwin90
    Tilwin90 Posts: 662 Critical Contributor
    Mburn7 said:
    my only real issue would be with your Mistcaller ruling, but like you said there isn't much to go on there no matter what is done
    Usually this is another lesson I've grasped from MaRo, namely sometimes picking the simplest solution is the best solution. The state of the game is where it is now (and namely the high level of bugs), because the code is not built on top of a very strict set of rules. Therefore the team ends up with weird patches trying to "fix" infinite combos and bugs due to weird interactions that were not considered whenever a new feature was created.

    This is why I'm so obsessed with those very strict rules. If the conceptual foundation is built on a set of sound rules, then the programming is easy as you only translate those rules ingame and you're done. Even building new cards would then theoretically become just as simple. Whenever you run into a collision (such as you start having competing replacement effects let's say), in theory if there is a stable and consistent design phase, those issues would already arise there.

    Unfortunately right now new mechanics kept being piled up on over the other and exceptions being entangled into exceptions. The best example here is Jaya's ultimate that grants a spell full mana but doesn't allow you to actually cast the card the same turn is just bogus! From a rulings and logic point of view, not implementation. Now whether it is a bug or not, we can't even know, because these rules are not written anywhere. So of course this issue explodes further into the player base.

    At a certain point I considered starting a comprehensive set of rules for the player base so we can atleast have consistencies and inconsistencies stored somewhere and be able to keep track of them... but naturally I've been caught up with other projects and lost focus of that initiative.
  • Laeuftbeidir
    Laeuftbeidir Posts: 1,841 Chairperson of the Boards
    Jaya is indeed buggy, as @brigby has confirmed.

    I vaguely remember the last patch notes mentioning that some card texts have been changed to follow their rules.. I don't think there are actually such rules. Maybe we all should use one of the q and a questions to show them that we'd love to have some insight from their perspective
  • Kinesia
    Kinesia Posts: 1,621 Chairperson of the Boards
    I don't like the "timestamp approach" for precedence because this isn't shown in game and you need to remember it in your head. Things need to be consistent for beginners. They need to _always_ operate in a predictable way and the timestamp thing messes that up. In another game they evaluate stuff from left to right always and that works because you can see it onscreen...

    I think the best way to deal with the Leader/Mistcaller thing is have (whatever answer is chosen, though I prefer Leader getting reinforced) to be written on Mistcaller in some manner. Adding a proviso to that one card is better than having a proviso on Leader (which is in many places).
    Adjusting wording for clarity is fine since we already aren't just putting the paper wording on cards, there's no problem with occasionally having to add extra to make more sense.
  • Tilwin90
    Tilwin90 Posts: 662 Critical Contributor
    Knowing your background you probably understand very well why I'm not a fan of specific card rulings, especially if they don't fit in a templating. Those kind of exceptions tend to clutter one on top of the other and lead to a system very difficult to control - as you have to keep track of all those exceptions not only in design but also in implementation phase.

    Competing replacement effects will exist, and the more cards are added to the game, the more we need a clear generic resolution in this direction. Since MTGPQ is a "fast" automated game thinking to give somehow the player the option to choose between all those effects would probably slow the matches tremendously... not to mention it would require severe adjustments to the user interface.

    As for beginners, that is the beauty of these rules being plugged into an engine for MTGPQ - you no longer have to worry about managing them yourself.
    Let's look at triggered effects. Right now a beginner won't figure out what's the order in which they get to resolve - think of the simple landfall stack of Part the Waterveil + Prism Array. It is much more advantageous to play the Array followed by Waterveil so that for each 5+ match you first draw the cards, then give them 10 mana.
    But for triggered effects, we see once again a timestamp rule applied here. Hence for consistency purposes, I think it would be easier if for replacement effects a similar strategy were picked (whichever ends up making sense as long as it's a global rule).

    On the other hand replacement effects are quite complex (though in terms of paper magic I might be completely wrong here - but I would look here only in the more recent sets for examples that violate this assumption). And I still hope high complexity cards get designed at higher rarities (rare & mythic rare). Therefore newbies will rarely run into this situation until they get such cards, or both them and their opponents end up playing different cards with competing replacement effects. It's not unheard of, I just don't expect it to be that often to be a significant number of cases.
  • Kinesia
    Kinesia Posts: 1,621 Chairperson of the Boards
    @Tilwin90 you are right about me understanding and agreeing we need a very fixed strict set of predictable rules and implementation as the foundation for the crazy weird things cards can potentially add.
    I just disagree that the existing timestamp principle should be part of it. I don't like that it exists now because it's not obvious, it's not written anywhere, it's not on the cards, there's no reason to expect it.

    And things could be done to make it more obvious (like flicker highlighting a support or creature as it activates, so you can see the order and go and click on them if you are curious about what just happened. (going into the battlelog is too involved for a quick check about something that should be obvious.)) but I don't like that order matters at all...

    But maybe there aren't better options to using order?

    I just want that when there _are_ exceptions to what people might reasonably expect that they be written on the cards or explained in a tutorial rather than being taught be trial and error and confusion.

    The rules being written on the cards is an important thing, so it needs to be accurate and not rely on assumptions (except the most basic ones that everyone is taught from the beginning of the game.) and sometimes that means that (pragmatically) some cards will end up needing special treatment and that should be written on them. Some of the issues you mention about in the first paragraph are because these things are just "done" rather than every bit of it being written down solidly somewhere. It's from the years of implementation when nothing was documented and the card wording was never precise.

    But... Thinking more about an implementation fix... If the problem is people's understanding (which it often is) then just indicating what is happening better starts to appeal more.
    When a token comes in with mistbinder, the first token picture can show up then mistbinder can flash and the token can disappear. (Important note, with multiple tokens only the first one should ever do this, and very quickly! no slow animations)
    If there is a leader out then the token appears, the leader flashes and reinforces and the token disappears.
    And people can see the difference between these cases fairly easily then.

    If there is timestamp stuff going on doing the same type of depiction still works but it might take ages for people to realise why sometimes mistbinder takes precedence and sometimes the leader... That's the messy part still...
    For so much existing stuff people really should know which supports and creatures were played in which order but that's horrible information to display, the complexity level is already high enough, and what happens when something is reinforced? Should it jump to the top of the stack?

    We absolutely can't make people choose order for things, but the existing system has hidden nastiness and finding a way to display that nastiness would help in some ways and hurt in others. There's nothing "nice" here in the generalities.

    But I do like the current balance of leader... Maybe the place to specify this is in the leader rules somewhere since it is a more general ruling than a specific card.  (The "change the documentation" solution to a bug...) And leave the rest of timestamp mess to the background since it is too big a can of worms in a gordian knot to be dealt with any time soon...

  • [Deleted User]
    [Deleted User] Posts: 0 Just Dropped In
    edited November 2018
    "- Objectives that require creatures "entering the battlefield" - they count both creatures and tokens and are probably the most inclusive of all"

    I think you should add that graveyard/library to battlefield is included in this section. The lack of this information may cause any devs reading this to omit that function. 

    And i am okay with the timestamp thing. Its certainly more consistent and over time that consistency will be the pattern that makes more astute/detailed people aware. 

    And then a tutorial could be made for it. 
  • Kinesia
    Kinesia Posts: 1,621 Chairperson of the Boards
    jimpark said:
    "- Objectives that require creatures "entering the battlefield" - they count both creatures and tokens and are probably the most inclusive of all"

    I think you should add that graveyard/library to battlefield is included in this section. The lack of this information may cause any devs reading this to omit that function. 

    And i am okay with the timestamp thing. Its certainly more consistent and over time that consistency will be the pattern that makes more astute/detailed people aware. 

    And then a tutorial could be made for it. 

    More tutorials to cover the weird things would be good!

    (If there's ever something they feel weird making a tutorial about it's probably a sign they should fix it!)