Goblin Test Pilot shenanigans

There's a handy combo that can be used to get an unlimited amount of copies of almost any creature, which consists of enchanting said creature with Splinter Twin and having an Intruder Alarm on the battlefield. (This way each time you create a copy of the creature, Intruder Alarm will untap the creature, which means you can create another copy, and so on.)

It's fun to think what happens with certain creatures when they are copied without limit. One such case is Goblin Test Pilot. This can create some very interesting rules nightmares.

Goblin Test Pilot has power 0, so it can't be used to win the game by attacking (unless something boosts all your creatures). However, it has an ability that deals 2 damage to a target creature or player. (Because the copy will have haste, you can use it right away.) The thing is, the target is chosen at random. This creates interesting situations.

The game supports the notion of "shortcuts". In other words, if you wanted to create a thousand copies of the goblin, you don't have to go through the motions one at a time, but you can propose a shortcut. You can simply demonstrate how the combo works and say "I create a thousand copies of the goblin; they'll all end up untapped at the end." If your opponent has nothing to interrupt the combo, then they can agree with the shortcut.

However, suppose that now you would want to activate the ability of each copy. Can you shortcut this? Normally you could, but in this case you can't because the target is chosen at random. You pretty obviously just can't propose a shortcut for a repeated random effect. You would need to choose the random target individually for each activated ability. So what exactly are you supposed to do in this case? You can't take forever to activate them.

This isn't just a "troll" combo, however. There's a way to arguably use this combo to win, by following this procedure:

1. If there are no untapped goblin copies, create a copy and let Intruder Alarm untap all creatures.
2. Activate the ability of an untapped goblin copy.
3. If it targets your opponent, one of his or her creatures, or one of your goblin copies, let it resolve and then jump to step 1.
4. Else (in other words, if it targets you or your original goblin) do not let it resolve and instead jump to step 1 in response.

While this is not a formal proof, this informal argument can be used to show that you will eventually deal enough damage to your opponent to win the game, no matter how many iterations it takes. It doesn't really matter if this takes ten iterations or ten million iterations, eventually you will have dealt enough damage to your opponent to win.

Can you propose this kind of shortcut? The official answer is no: You can't. The reason is that the number of iterations is not fixed, but random, and that just can't be shortcut. The rules of the game don't support this.

This creates a curious situation where, at least in a tournament, you would probably be disallowed from running this loop, or even imposed a game loss for stalling, even though there's nothing illegitimate about the combo and you are not really stalling. You are just doing what the cards say, without any kind of stalling. However, if the loop is taking hours, you won't be able to just continue it in an actual tournament. You can't shortcut this either (at least if the judges are strict with the rules of the game.)

Is pile-shuffling useful?

I posit that it is not, and here's my argument.

"Pile-shuffling" is the method of distributing the cards into a number of piles, and then just collecting the piles together. This is rather different from the traditional "mash shuffling" and "riffle shuffling" methods.

This is an important fact: Pile-shuffling does not evenly randomize your deck. This might sound like something self-evident and trivial, but nevertheless surprisingly many people have all kinds of misconceptions about it. Some people believe that pile-shuffling two times into a different number of piles is "sufficient randomization". Many even mention prime numbers (even though they have nothing to do with how randomized the deck will become.) Pile-shuffling does not evenly randomize your deck even if you put each card on a random pile.

Assume that at the end of a game you simply collect all your lands and put them on top of your library, and then pile-shuffle for example into seven piles. This means that you know that each 8th card in your deck will be a land. This is obviously not even randomization. Even if you couldn't tell which land will come after the next seven cards, it's still not randomized because you know for certain that it will be a land. This ought to be pretty obvious.

Moreover, if you did this, it would be effectively mana-weaving (ie. deliberately distributing your lands evenly in your deck, with no randomization afterwards), which is illegal.

Most players who pile-shuffle will mash-shuffle or riffle-shuffle extensively afterwards, and they argue that this is sufficient randomization which nullifies the "mana-weaving", and therefore it's not cheating. And that's the crucial point: If they are going to sufficiently randomize it afterwards, undoing any ordering that the pile-shuffling achieved, then the pile-shuffling was a complete waste of time because it did nothing useful.

Pile-shuffling does not increase the randomness of the deck (by its very nature), and the deck is going to be randomized afterwards anyways, so why exactly do it? What's the use?

Some may ask "why not? What's the harm?" There's no other harm except that pile-shuffling takes time, and thus it's a complete waste of it. So why waste time on a procedure that achieves nothing useful?

Some people argue that pile-shuffling is useful to count your cards (in order to verify that no card ended up in the wrong place during a game, and that there aren't any extra cards). Ok, that's fine. However, especially tournament players often pile-shuffle several times. These extra shuffles do not have even this excuse.

The main reason why people pile-shuffle is because they feel that normal mash-shuffling doesn't "separate" cards enough from each other. They feel that pile-shuffling separates the cards from each other in the deck, and thus increases randomness and evens out the deck more (especially in terms of land distribution). But this is once again borderline mana-weaving: If you feel that your mash-shuffling is not randomizing the deck enough, and thus you feel the need to pile-shuffle to compensate, then you are borderline mana-weaving, ie. borderline cheating. If you argue that your mash-shuffling is enough to randomize the deck afterwards (and thus undo any possible mana weaving), then you are arguing that the pile-shuffling was indeed useless and a waste of time.

I find it curious how defensive people get when these things are brought up. Many, if not most, players will vehemently defend pile-shuffling no matter what arguments against its usefulness are presented. I have yet to find a player that simply agrees.

(Often the conversation will quickly start going in circles. When you argue that pile-shuffling effectively amounts to stacking/manaweaving your deck, they will argue that the mash shuffling afterwards will undo any such stacking. When you then point out that they just confirmed that the pile-shuffling achieved nothing useful because of the mash shuffling, they will insist that it was useful because it separates clumps of lands etc. In other words, you can point out, they are indeed stacking/manaweaving with the pile shuffling. And in circles the conversation will go...)

If you don't think pile-shuffling is all that slow, watch this video. (Note that the several pile-shuffles the player does eg. starting at 2:25 in the video have zero benefit in terms of deck randomization because of the rather massive amount of mash shuffling done in addition to them.)

An oddly-worded replacement effect

In Magic, replacement effects are very recognizable because they typically use the word "instead". In fact, the vast majority of them conform to the template:

"If (something) would (do something), (do something else) instead."

For example, Rest in Peace says:

"If a card or token would be put into a graveyard from anywhere, exile it instead."

This form is so ubiquitous that when one gets used to it, a card like Knight of the Holy Nimbus sounds very strange.

It says: "If Knight of the Holy Nimbus would be destroyed, regenerate it."

Note how it almost conforms to the standard template, except that it does not use the word "instead". In fact, it doesn't seem to conform to any standard template for replacement effects. These templates are defined in rule 614.1, and are (paraphrasing):

• Effects that use the word "instead".
• Effects that use the word "skip".
• Effects that read "[This permanent] enters the battlefield with ...", "As [this permanent] enters the battlefield ...", or "[This permanent] enters the battlefield as ..."
• Effects that read "As [this permanent] is turned face up ..."

None of those templates seem to fit Knight of the Holy Nimbus. So what exactly is it?

It turns out that this is a special wording defined in rule 701.12b. Said rule effectively states that

"If [this permanent] would be destroyed, regenerate it."

means

"If [this permanent] would be destroyed, instead remove all damage marked on it and tap it, and if it's an attacking or blocking creature, remove it from combat."

The "instead" is implied in this particular template.