Tuesday, July 30, 2019

Why MtG rulings discussion is important

In my last (well, I suppose now second-last) post in this blog I explained how the draconian rules enforcing and moderator behavior at the MTG Salvation forums completely killed my passion for the game and its rules, and why I stopped posting in this blog. It is my understanding that the forum is actually moving more and more towards an even more draconian attitude when it comes to the rulings forum, where less and less discussion is allowed.

This is actually a very common thing when it comes to MtG rulings forums out there: Many (perhaps most) of them are absolutely and completely draconian: Only one question and one singular answer from an approved judge is allowed. Period. In many forums everybody else is banned from giving any answer (or if not banned per se, any further posts and discussion is generally quickly removed and the thread locked.)

Honestly, I never understood why this is done, nor why it seems to be so common. The rules of the game are very complicated, and judges are sometimes wrong. They are people, and they are not perfect. The people who understand the entirety of the Comprehensive Rules inside out, from beginning to end, and every single one of even the most complicated and obscure tidbits, is quite small. There are literally tens of thousands of L1 judges, and even L2 judges, out there that get some things wrong, and don't know every single tiny detail and complicated interaction.

And, as it sometimes happens, sometimes the Comprehensive Rules themselves are actually deficient and might need improvement and corrections. I believe that I myself once noticed such a defect in the rules, which eventually led to its fix.

Some time in early 2013 I noticed a curious situation involving an effect instructing a player to cast a spell (without paying its mana cost), and that spell having a mandatory additional cost involving revealing a card of a particular type from the player's hand. I asked about this at the MTG Salvation rulings forum. Back then the forum was still more open-minded, and an actual lengthy discussion ensued. A bit later I made a blog post about that exact question I posed: A hole in the MtG rules?

As a result of that discussion, one of the more senior judges participating in the discussion asked the question at the official Wizards of the Coast rulings forum (which still existed back then), and a similarly lengthy discussion about it ensued there.

Eventually this led to fixing the hole in the Comprehensive Rules with the addition of rule 118.8c: "If an effect instructs a player to cast a spell “if able,” and that spell has a mandatory additional cost that includes actions involving cards with a stated quality in a hidden zone, the player isn’t required to cast that spell, even if those cards are present in that zone."

What I find particularly interesting is that the release notes for the set that introduced that rule change specifically mentioned the cards Wild Evocation and Disaster Radius as an example of such an interaction. These were the exact cards I used in my original question (and the blog post made based on it)! From all the possible cards that could have been used as an example, they chose the two that I had used. This led me to believe that it was precisely my question that eventually led to this rule fix.

I think this is a perfect example of why allowing free discussion in rulings questions is important.

If back then the MtG Salvation rulings forum had been the absolute draconian type where only one answer from an approved judge is allowed on any question, and zero discussion, what would have likely happened is that some judge would have just given an answer like "in a tournament you would need to call the judge to verify that you don't have a creature card in your hand", and that's it. No discussion would have ensued, and this hole in the Comprehensive Rules would probably had never been patched, and it would still exist to this day.

Sunday, January 14, 2018

Why I'm no longer posting in this blog

Short answer: The administrators at the mtgsalvation forums successfully killed my passion for the game.

Long answer:

Since I started playing Magic the Gathering, some time in 2010 or such, I always found the complex interactions between different cards, and the difficult rules questions, very interesting. I quite quickly found the mtgsalvation forums, and the rulings forum was to me the most interesting one in the entire site. I loved learning the game there, asking questions, and reading other people's questions and the answers to them. It was extremely didactic, informative and interesting.

In fact, many of the posts in this blog are directly from questions that people asked in that forum (or questions I asked myself).

Eventually I became so acquainted with the rules that I could start answering people's questions myself. It was actually something I loved to do. In fact, no matter how simple or rudimentary beginner question it was, I loved to teach people the game, even the basics of the game. Be it an extremely complex question about an extraordinarily obscure interaction between cards that requires profound knowledge of the intricacies of the comprehensive rules, or be it just a simple question about how eg. trample works, I loved to answer those questions, and teach people about how the game works, at all levels. I would say that I knew the rules of the game better than most L1 judges (perhaps even better than some L2 judges).

There was one problem, though. Even though the mtgsalvation rulings forum would have been ideal for this kind of interaction between people asking questions about the game, and other people answering those questions, the forum was not run (and probably still isn't run) like that. It's much more draconian.

For one, the forum implements a rather draconian infraction system. I have never seen any such system being used in any other forum I have ever been to (there probably are some forums out there with similar systems, but I myself have never encountered any). If you violate the rules, you get an infraction. Get too many infractions, and you may be penalized in some way.

That all in itself wouldn't be bad. Sure, if someone insults somebody, or attacks somebody verbally, or harasses somebody, is overtly rude, condescending, or shows other form of inappropriate behavior, it's sensible to put a stop to such a behavior.

That's not the problem. The problem is that you could get infractions from the most innocuous things, and completely at random. For example, if you correct an error in somebody's answer, you could get an infraction for "nitpicking". Not consistently, though (which makes it worse). Completely at the whim of whichever moderator happened to be there at the moment. I witnessed over the months and years dozens and dozens, perhaps hundreds, of instances of somebody correcting someone else's erroneous answer, and seemingly completely at random perhaps about 10% of those corrections got an infraction. I swear there was no consistent pattern to it; it was completely random. (And no, in most of those instances it was not a question of somebody actually nitpicking about some complete triviality, like a completely inconsequential minor detail that wasn't relevant to the question at hand. Oftentimes the correction was completely valid and pertinent to the question at hand, yet some moderator still issued an infraction on it, even though you could find at the same time very similar posts with no infractions.)

What's worse, if you answer the "wrong" kind of question, even if that question is completely related to Magic the Gathering, you could get an infraction for "spamming". Yes, "spamming". For example, if a beginner player made a follow-up question to their original question, for example asking for an actual example of cards that do something related to the original question, and you answer that question, you can get an infraction for "spamming". It doesn't matter if the question is related to the original post in the thread, and the answer is 100% correct, you can still get an infraction.

As you may have guessed, I got myself infractions for precisely these kinds of things. Every single infraction was completely ridiculous. I never misbehave, I never said anything bad to anybody, nor attacked or insulted anybody, and all my posts were always on-topic, about Magic the Gathering, and the thread in question. The "worst" offense I ever did was making, completely by mistake, a reply post that wasn't actually an answer to a question that was being presented (the post was something akin to, paraphrasing, "wow! that's a really cool flavor!". I made the post by mistake because I thought I was in the general forum rather than the rulings forum. Explaining the mistake to the moderator didn't help. The infraction stood. No mercy, no leniency, no understanding.)

Because of all these random infractions, for the most ridiculous of things, the climate in the rulings forum was always really oppressive. You could never anticipate when some random moderator would randomly decide to give you an infraction for the most ridiculous of reasons, no matter how on-topic, proper and correct your post may have been.

And I got banned from the rulings forum because of these infractions. In particular, the last infraction I got before the ban was precisely what I described above: A beginner asked a question about whether something worked with some particular card (I don't remember the details because it has been so long, and I obviously have no access anymore), and the answer was no. He then made a follow-up question asking if there are any cards for which that thing works. The question was completely on-topic, related to the original question, and related to the game. I answered, completely correctly, by giving an example of a card for which that thing worked.

Completely at random, a moderator decided to give me an infraction for "spamming".

That labeling of "spamming" has always irked me. Actual, real spam was always a problem in the forums, with spambots flooding the forums with spam posts (ie. those kinds of automated posts that advertise all kinds of products and so on, that are completely unrelated to anything in the forum). Whenever I saw such posts, I diligently reported them for being spam.

By labeling someone's answer (correct answer, may I add) to someone's question about Magic the Gathering as "spam", that's in essence calling that post worthless garbage. I always felt it as an insult. I always posted to try to help people, and these moderators were labeling my posts worthless garbage, and giving me an infraction because of them, even though the posts were always on-topic, and never out of line.

I had complained about this, in private, to the moderators in question several times in the past. I did so this time as well.

I obviously cannot know what happened behind the scenes, but I suspect that this particular moderator decided to teach me a lesson, and convinced the other staff to ban me from the rulings forum.

And mind you, this ban came completely out of the blue, and was permanent. No warnings, no grace periods, nothing. There was no warning like "if you keep doing this, you will be banned". It was not a temporary ban to teach me a lesson. No. No warnings, nothing. Completely out of the blue, a lifetime ban from the rulings forum, with no possibility of appealing the decision.

And why? Because I answered somebody's question about Magic the Gathering.

The rulings forum was the main reason why I was a regular visitor of the site in the first place. As I described in the beginning, I was very passionate about the game and its rules, and I loved to ask, read and answer questions related to the game. Banning me, permanently, from the rulings forum was in essence no different from banning me entirely.

I tried to appeal to reason in the proper appeals thread. It made absolutely no sense to ban someone (and ban them permanently for that) for answering people's on-topic questions about the game. It made absolutely no sense for the forum rules to punish people for answering people's on-topic questions.

What I encountered in that thread was a completely unwavering hive mind. Something like 4 or 5 site moderators and administrators participated in that discussion, and they all behaved like clones of each other, repeating the same mantras about the forum rules, and never conceding anything, never presenting any dissenting opinions, or anything.

At one point I posted a list of something like 5 questions to these moderators. These were questions like (paraphrasing): "Should the purpose of the rulings forum be to teach people how to play the game?" "Should people be able to correct errors in other people's answers without the fear of receiving an infraction?" and so on. Not a single one of those moderators answered even a single one of those questions, even though I asked them to do so several times. They completely ignored the questions, repeatedly.

It's hard to describe the atmosphere in that discussion, but it really felt like speaking to a hive mind, or a cult. The forum rules were absolute and unchangeable, and the moderators were always right when implementing those rules and giving infractions, and at no point did any moderator present even the slightest sign of dissent towards the others, or of understanding and leniency towards me. Even a simple request of them stopping labeling people's clearly non-spam posts as "spam" had absolutely no effect. Even that one word could not be changed in the rules.

It became quite clear that I was permanently banned, with absolutely no possibility of appeal, and they would not listen to any reason or arguments. So I just got fed up and got myself completely banned from the site. It made no difference to me, since if I was banned from the rulings forum I could just as well be banned from the entire site.

I could have easily created a new account. In fact, a year or so after that incident I did exactly that, just to try if it would work, and there was no problem. I created the account, and could post just fine. However, I never used that new account for anything but a couple of initial posts.

This whole incident with the forum administrators just killed my passion for the game, and my desire to keep interacting in the forum. The oppressive nature of the rulings forum, and the amazingly oppressive cult-like behavior of the administrators, somehow just gave me a really bad taste in the mouth to even think about participating in the forum anymore. Even though I read through posts in the rulings forum a couple of times, the passion, the willingness to answer people's questions and teach them the game, just wasn't there anymore.

And the amazing thing about all this is that the mtgsalvation forum is, in essence, the only viable MtG forum out there. In the past Wizards of the Coast had their own forum for precisely this kind of thing, and it was quite awesome. People would ask sometimes really complex questions, and sometimes quite long threads discussing that situation, and its implications, would ensue. (In a few instances I even witnessed such a question resulting in actual rules changes in the game.) But then WotC, for some reason, ended that forum. And mtgsalvation became the only viable forum out there. (There are, of course, myriads of smaller MtG related forums out there, but they are usually very small and not very active. And many of them have even more draconian rules, such as not allowing anybody to answer any questions in their respective rulings forums.)

Given that lately the MtG community has been slowly been overtaken by social justice warriors, making the whole community even more oppressive, I suppose I don't even long back anymore. It's just not for me. The mtgsalvation administrators killed my passion for the game, and now social justice warriors are killing the community, so I suppose that's it. It's just not for me.

But it's a shame, really. I loved creating these blog posts.

Wednesday, May 24, 2017

Forced to cast a split card... What to do?

Suppose there's an Omen Machine on the battlefield. Your turn comes, and its effect makes you exile the top card of your library, which happens to be Wear // Tear.

The machine doesn't give you a choice: You have to cast it, if possible. However, there aren't any enchantments, nor any other artifacts, on the battlefield. However, you really don't want to destroy the machine, because you like it.

Question: Could you choose to cast the Tear half (ie. "destroy target enchantment"), have it fail because of a lack of legal targets, and have the card remain in exile?


A few clarifications for those readers who are unsure how Omen Machine (and such similar effects instructing players to cast a card) works: When an effect instructs a player to cast a card ("if able"), and there is no word "may", that means that the player has no choice, and is forced to cast the card, if it can be legally cast. For example, if the card had been a Doom Blade, and you are the only player who controls a non-black creature, you would be forced to cast it targeting your own creature. You can't choose to not cast it (nor can you choose an illegal target for it.)

However, if there are no non-black creatures on the battlefield, in that case Doom Blade cannot be legally cast (because there is no legal target for it). In that case the card is not cast and simply remains where it is (which in the case of Omen Machine is the exile zone.)

With a card like Wear // Tear, however, the situation is a bit more complex. When the effect instructs you to cast a split card, you have to choose one of the sides to cast (fusing is not an option because that can be done only when casting from your hand; here we are casting from exile.) Perhaps you could simply choose the Tear half, and then have it fail to be legally cast (because there are no legal targets for it) and have it remain in exile?

However, the correct answer is that if there are no enchantments on the battlefield, you have to choose the Wear half. Choosing the Tear part is not an option. The reason for this is a bit complicated, though. There is no direct rule in the Comprehensive Rules that states this, and instead it has to be inferred more indirectly.

We have to start by pointing out that in this situation casting Wear // Tear is an "effect", as per (the relevant part of) rule 609.1:
609.1. An effect is something that happens in the game as a result of a spell or ability.
Anything that happens as a result of a spell or (as in this case) ability is an "effect". This includes casting a card, if it's the ability that's instructing a player to do so.

Rule 608.2d, in turn, states (emphasis mine):
608.2d If an effect of a spell or ability offers any choices other than choices already made as part of casting the spell, activating the ability, or otherwise putting the spell or ability on the stack, the player announces these while applying the effect. The player can’t choose an option that’s illegal or impossible, with the exception that having a library with no cards in it doesn’t make drawing a card an impossible action (see rule 120.3).
Although it might be completely trivial and unnecessary to state, which half of a split card to cast is a choice (made during the casting process). For completeness sake:
708.3. A player chooses which half of a split card he or she is casting before putting it onto the stack.
Part of the process of casting a spell is to check if can be legally cast:
601.2e The game checks to see if the proposed spell can legally be cast. If the proposed spell is illegal, the game returns to the moment before the casting of that spell was proposed (see rule 720, “Handling Illegal Actions”).
Since the choice of half was what made the casting illegal, it's an invalid choice, prohibited by rule 608.2d above. The player has to make a choice that makes casting the card legal, if possible. In this situation choosing the Wear part makes casting the card legal, and thus that choice is mandatory.

Wednesday, August 17, 2016

Splendid Genesis

Splendid Genesis is not an actual real Magic card (not even an "un-card"). Thus it's not legal in any way in any format, because it's not an actual valid card at all.


It was commissioned by Richard Garfield (the creator of Magic the Gathering) to celebrate the birth of his first son. Only 110 copies were created (ie. one printing sheet), and he handed these copies to friends and family. Even though this isn't a real Magic card, it's nevertheless a humongously expensive collector's item. (As far as I know, you might be able to buy one for some tens of thousands of US dollars, if somebody is willing to sell their copy.)

So why am I writing about this non-card? I want to discuss a common phenomenon I have seen surrounding this card. Namely, many players express the desire to try this card in an actual game, because it sounds so fun.

I would posit, however, that this is a rather nonsensical idea for two major reasons: One rules-technical, and another practical.

I consider this a highly interesting card from a psychological perspective. Not because it would be fun or reasonable to play (for the reasons I describe below), but because it so easily fools even experienced players into thinking that it would.

The technical reason why this would be a completely nonsensical card to use in an actual game is that it interacts abysmally poorly with the rules of the game. The rules just don't support the mechanic depicted in the card. If you tried to play this card in an actual game, you would run into tons of rules interaction problems and situations that are just not supported by the rules.

As one, and the most obvious, example, this messes up completely with the notion of the "owner" of a card. There are myriads of rules and other cards that refer to the "owner" of cards, and this would mess up with that quite badly, and raise tons of conflicting situations. The rules of the game simply don't support the notion of the ownership of cards changing mid-game. And, as said, this is just one example.

The practical reason why playing this card is rather nonsensical is that, when you think about it for longer than a few seconds, this actually isn't such a fun idea in an actual game. I mean, this requires three players, and the third player is supposed to... do what, exactly? Just sit there watching the game, and just hope that one of the players happens to draw this card and happens to be able to play it? Chances of this not happening at all are quite high. Personally I would much prefer playing a three-player game from the get-go, rather than have one of the players just sit down there with nothing to do, just waiting for the random chance of joining the game. This card is not so fun in practice, in an actual game. It would be rather boring, in fact (especially for the player chosen to not play from the start.)

And this isn't even going into the fact that even if the card were to be played during a game, it would completely mess up with the deck contents, with each player essentially having random cards from two decks, with no guarantee that they will be playable (eg. because of too few lands, or too few lands of the proper mana colors.) Most likely the game would just become a random mess that screws one of the players, making it completely unfun.

Notice also that all cards are reshuffled into three decks, which effectively means restarting the game (except for life totals), but the card says absolutely nothing about drawing opening hands. In other words, the game is reset and becomes a top-deck mode game.

Some people would still protest and say that they would still like to play this card. The rules problems can be circumvented with house rules invented on the fly. Well, if you want to experience this, you don't need this card, nor do you need to have a third player waiting doing nothing: Just take two decks and shuffle them together and split it into three, and then start the game without opening hands. It will be pretty much the same thing as what this card would do. (And let me assure you that it would not be much fun. I have actually tried "top deck mode" Magic, ie. a game without opening hands, and it was random and boring as heck. And that was with normal constructed decks, not randomized ones.)

But yeah, I find the card interesting for this reason, ie. how easily it fools people into thinking that it would actually work and be fun to play.

Sunday, June 12, 2016

Are 7 mash shuffles enough?

An extremely prevalent sentiment among most players is that mash-shuffling is not enough to evenly randomize the deck. They have the strong feeling that cards will not be "separated enough" from each other, and that if, for example (the most common example), they put all their lands on the top of the deck and start mash-shuffling, they will end up with huge clumps of lands, and huge clumps of non-lands (and thus they will either mana-flood or mana-screw). They feel that most certainly 7 mash shuffles (which is the oft-quoted figure) is not even nearly enough. For this reason they will often resort to pile-shuffling to "separate the cards". No matter how they are explained that 7 mash shuffles is indeed enough, and that nothing else is needed, they just can't accept it. They might accept something like 20 or 30 mashes, but certainly not 7.

But I'll try to explain it.

Let's assume that the deck uses decent sleeves (ie. not those cheap transparent thin sleeves intended for double-sleeving that can get sticky and pretty much glue cards together). Let's consider two cards that are adjacent in the deck, and let's examine how their relative separation will behave during mash shuffling.

You'd agree that with one mash, there's roughly speaking an approximately 50% chance that at least one new card will be inserted between them. Question: What are the chances that they will still be adjacent after 7 mash shuffles, on average?

Answer: Approximately 1 in 128, or about 0.8%.

Ok, there's only a very minuscule chance that they will still be adjacent after 7 mash shuffles. But they will still very likely to be very close to each other, right?

No. The thing is, the more separated they are already of each other, the more likely it is that more cards will be inserted between them. If you think about it, you'll realize that, in fact, their distance will, on average, roughly double with each mash shuffle. This means that their separation will grow exponentially with each mash.

What does this mean in practice? On the first mash, their separation will increase on average by 0.5 cards (which is what a 50% chance of a card being inserted between them means). This separation will, on average, double with each mash. Thus their average separation will roughly double the 0.5 seven times, ending up with an average separation of 64 cards. (And this is the average separation between them, not the maximum. The maximum could theoretically be anything.)

Since there is (typically) only 60 cards in the deck, a separation of over that means in practice that the card "wraps around" in the deck, to the other side. In practice this means that it will end up pretty much at a random place within the deck. There's a big chance that the relative order of the two original cards in the deck we were examining will switch (probably somewhere around the 50% figure, which is exactly what should happen.)

Yet, no matter how precisely this is explained, most players will not accept it. They will trust their own intuition more than mathematics. And they will waste everybody's time with useless pile-shuffling, and mash-shuffling dozens of times.

Saturday, July 4, 2015

A non-existent mana cost

There's a principle (well, rule really) in Magic that goes like this: A non-existent mana cost cannot be paid.

What does this mean?

Consider this scenario: You have a Living End in your graveyard, and you cast a Snapcaster Mage, and use it to give the Living End flashback. Can you then proceed to cast Living End from your graveyard?


The answer is no, you can't. And the reason for this is the principle: A non-existent mana cost cannot be paid.

Living End has no mana cost. This is not the same thing as having a mana cost of 0. (If its mana cost were 0, then it would have a mana cost symbol with 0 on its upper right corner.) It has no mana cost at all. This means that it can't be cast in the normal way (because paying its mana cost is part of the casting process, and in this case that step cannot be done, because it has no mana cost.)

(Note that Living End has a converted mana cost of 0. However, this is a completely different and unrelated thing. That value is used only for effects that look for converted mana cost explicitly. Casting does not look at converted mana costs.)

Snapcaster Mage adds flashback to the card when it's in your graveyard, and it states that the flashback cost is its mana cost. However, as stated, the card has no mana cost! This means that it has no flashback cost either, and a non-existent cost can't be paid. Therefore you can't cast it using Snapcaster Mage either.

So how exactly is Living End cast, then? Using its suspend ability. Suspend works like this: If the card is in your hand, any time you could cast the card (ie. obeying timing restrictions for the card type) you may pay the suspend cost, which moves the card into exile with the specified number of time counters. At the beginning of your upkeep you remove one time counter from it, and when the last time counter is removed, you may cast the card without paying its mana cost.

That last part is the crucial difference: The effect allows you to cast the card "without paying its mana cost". Any effect that uses that wording bypasses completely the mana cost of the card, and thus we don't even look at what it is (or, like in this case, whether it even exists.) The effect instructing you to cast the card doesn't require paying any mana cost, and thus the card can be cast.

Consider Living End with these two cards:


Act on Impulse exiles the top three cards of your library, and allows you to cast them (from exile) until end of turn. Even though the cards are in exile rather than in your hand, the casting process is identical. Therefore you can't cast Living End this way, because you can't pay its mana cost. (Incidentally, you can't suspend it either, because the suspend ability can only be used if the card is in your hand.)

Chandra's third ability exiles the top ten cards of your library. You then choose an instant or sorcery card among them, copy it three times, and then you may cast these copies without paying their mana costs. This, thus, does allow you to cast (the copies of) Living End, as mana cost is irrelevant.

As an unrelated side note, notice that these two effects behave different with regards to timing restrictions.

With Act on Impulse you have to obey the timing restrictions of the card (in other words, if the card is a sorcery or a creature without flash, you can only cast it whenever you could normally cast a sorcery, ie. in your main phase when the stack is empty.) With Chandra's third ability, however, you cast even sorceries immediately, ignoring their timing restriction (ie. even if the stack is not empty, and even if this somehow wasn't your main phase.)

The reason for the difference is that in the former case the effect allows you to cast the cards during a time period (ie. "you may cast these cards until (some time in the future)"), while in the latter case the effect instructs you to cast the cards immediately, while the effect is resolving. Whenever an effect instructs you to cast a card immediately, you do so disregarding the card's type; whenever an effect allows you to cast a card during a period of time (ie. until end of turn or whatever), you have to obey the timing restrictions of the card type.

Saturday, June 6, 2015

The problem with shuffling in MtG

Most competitive card games, where each player has a deck of cards that needs to be randomized, have one very major problem: Experienced cheaters can masterfully manipulate and "stack" the deck while shuffling, without their opponent or anybody else noticing. (This kind of cheating is sometimes caught on camera. With camera footage we have the advantage of seeing the shuffling as many times and as closely as we want, and in slow motion. In a real-life situation it's much harder, especially if we don't know what to look for, and sometimes even then.)

Experienced cheaters can stack the deck by moving certain cards to the top or the bottom of the deck.

To minimize the possibility of cheating, MtG tournament rules require for the opponent to also shuffle the deck afterward. The problem with this is that even though you can't stack your own deck, you can do it for your opponent's deck. For example you can mana-flood or mana-screw your opponent by stacking their deck appropriately.

Poker doesn't really have this problem because if you shuffle the deck, you have to present it to an opponent, and said opponent must only cut the deck once. (In fact, cutting it more than once, or even outright shuffling it, is forbidden at most places. It must be cut, and cut only once.) This way neither player can manipulate the deck. The shuffler can't know where the opponent will cut the deck, so there's no way to make certain cards end up on the top. (The only exception to this is that if both players are working together, and the other player cuts the deck where the shuffler "marked" it. This is a common cheating tactic in poker, but it only works if two players are working together, and only if they are sitting side by side on the table, as the cut is always made by the next player.)

Many have suggested using this same principle in MtG. In other words, shuffle your deck, and then your opponent cuts it once, and that's it. However, unlike in poker, this isn't a very effective anti-cheat measure in Magic. Yes, it prevents you from getting the cards you want on the top (or bottom, in the case of your opponent's deck in some situations), but there's another cheat that a single cut doesn't prevent: Mana weaving.

Mana weaving is distributing the lands evenly in the deck, so that you get a steady supply of lands and do not get mana flooded or mana screwed. An expert cheater can more or less easily mana weave their deck (eg. by shuffling in such a way that most lands go eg. to the bottom of the deck, and then mash-shuffling that bottom part into the rest of the deck once.) This is blatant cheating, of course, because the deck is not randomized.

And the thing is, a single cut to such a deck isn't going to undo any such mana weaving. And that's why the poker way doesn't really work in Magic. The opponent really needs to shuffle the deck in order to undo any possible mana weaving, and make the deck truly randomized. But, of course, when you can fully shuffle a deck, it allows cheating.

This is a dilemma that has no practical solution.

At the highest levels of poker cheating by shuffling trickery is impossible because players do not shuffle nor are allowed to touch the deck in any way. It's shuffled by a neutral dealer, employed by the tournament organizer or the casino.

In MtG tournaments the same could work if judges always shuffled the players' decks. The problem is that a typical tournament has over a hundred players and only a few judges. This solution is just impossible to implement in practice. (This could work on the top-8 matches, but for some reason it's not done that way. Perhaps it's not really needed either. The top-8 matches are always videoed and very closely watched, and it can be fairly assumed that nobody dares to cheat there. Although it does happen from time to time...)