This is redundancy to the max. 49 mana, 11 business. The average hand just has and plays one of the spells that wins the game.

Some quick notes on this subject:

Six copies of a card in your deck means you are 55% to have one in your opener and 65% to have one by turn three on the play, the critical turns for most Legacy combo decks. Through twelve copies, each additional one is about 5% added to both of those percentages.

Historically, nine cards has been the number for having one of a card early game when you only care about the first copy. Recently, Hive Mind has played eleven Pacts, as it wants extra copies of them to fight Daze or Stifle. Dredge lists have moved towards twelve dredge cards in order to ensure one is in their opening seven.

Tutors:

Tutors are another form of redundancy. For all intents and purposes they act as additional copies of the cards you want to hit.

Typically, there are two kinds of tutors. The first is those in the vein of Mystical Tutor that don’t actually put the card into your hand but instead let you trade a card in hand for what you want in the immediate future. If your deck requires assembling a large number of cards, these are usually a lot worse than they seem. Too often you need the extra cards in hand to generate mana or provide backup and can run low if your opponent starts entering an attrition battle with your hand with spells like Duress.

On the other hand, if your combo requires only a couple cards to win, you often have the extra cards to spare and can expend more to ensure you have exactly what you need. I have always felt more comfortable playing post-Mystical Tutor Storm as while you can’t just slam Ad Nauseam as easily, you are much better at topdecking in the mid game and have more resources to fight through soft hate with.

The second kind is in the vein of Diabolic Tutor or Mystical Teachings, where you break even on cards but expend a large amount of mana. These come at the cost of your fundamental turn. A good example of this is the Angel’s Grace—Ad Nauseam combo deck from Pro Tour Amsterdam. As hard as it tried to be a turn four deck, the fact it ran Mystical Teachings meant that in a fair percentage of games, it had to spend turn four finding the other half of the combo after doing nothing on an earlier turn. Combo decks still have mana curves, and it is important to pay attention to whether the lost tempo is something you can expend.

When your tutors double up on both parts of a combo, the odds stack up a lot better in your favor. If you have four tutors that get part A, you still need to find part B, which is only four cards. If your tutor gets both parts and you draw a tutor, you have eleven live cards instead of just four. If you draw one of the pieces, you have eleven live cards instead of four or seven depending on which one you drew. This is a huge advantage and a large part of why combo decks like Aluren choose Intuition over Worldly or Enlightened Tutor.

Velocity:

As is typical with Magic terms, velocity has its origins in a Mike Flores classic.

Velocity is a word that describes cantrip cascades and why Storm outguns control in the long game. Each cantrip you cast filters away blank draws, giving you virtual card advantage. In addition, cantrips find other cantrips to continue the chain, letting you continue this advantage the entire game until you have the perfect hand and they don’t.

The problem with velocity is that it just prevents you from drawing cards you don’t want. If the number of cards you don’t want starts approaching 100% of your deck, cantripping into what you need takes a longer time and is more likely to fail. This exact reason is why I lost at least one of my matches with Splinter Twin but, as I mentioned, is a risk you take when playing a deck designed that way. Cantripping into more cantrips to find a specific card is also a lot more about decision trees than tutoring. You have to evaluate how to see the most cards in a relevant time frame, and it is very easy to accidentally keep a Ponder you should have shuffled, fetch too early, or just cast a cantrip at the wrong time and miss seeing another card that would have increased the odds of you hitting.

The benefit is that you don’t actually invest cards into cantripping. This is exactly why Preordain is so good in control decks: at a cost of no actual investment beyond the one mana, you end up with an additional virtual fraction of a card or more. Ponder had the problem where you often could not prevent yourself from drawing what you didn’t want, though with fetchlands things change. A tutor would find what you need, but most tutors require you to two-for-one yourself or sacrifice large amounts of mana. When your deck is an array of answers, you can cast Preordain to set up lines of play with a multitude of cards without sacrificing the number of cards you have in hand to trade for theirs. As noted above, having a large number of cantrips also means that going late you are significantly less likely to draw blanks and can consistently outdraw people in the late game.

Auxiliary Cards:

A large portion of combo decks have to play cards that do nothing if drawn or are at best situational, but are essential to victory once you start comboing. Good examples are Narcomoebas in Dredge, Emrakul in the Basalt Monolith–Mesmeric Orb decks, Body Double in Protean Hulk decks, and almost any reanimation, Natural Order, or Show and Tell creature ever. These cards are effective mulligans, and certain strategies are better at dealing with them than others. Ideally you want to minimize the number of these cards you play while still being able to win. Part of the reason the various two-card mill-yourself combo decks in Legacy aren’t well represented is that they have to play a lot of these cards. Compare to say Storm, which only has Ill-Gotten Gains and Tendrils of Agony, which are still situationally useful, or Splinter Twin, which has none bar extra copies of the namesake enchantment.

Auxiliary cards are part of what makes Brainstorm so good. When you get to put one back into your deck and shuffle it away, it’s almost like the Brainstorm drew an extra card, as the blank in your hand was just taking up space and not going to get you a card worth of value at any point.

Vulnerability:

This is not about narrow hate. That always exists and will be addressed later in disruption.

Every combo deck operates in between various zones. The usual ones your opponents can interact with are the stack, in play, and the graveyard, with occasional library interaction. Decks that work almost exclusively out of one zone are the hardest to interact with in a fair way. Giving your opponent the smallest set of cards to interact with you will make it easier for you to just win. The larger the set of cards they can interact with, the easier it is for them to find one that destroys all your hard work. Almost every combo deck has to use the stack, with some exceptions involving things like Dredge. This is why counters are traditionally good against combo: they invest a bunch of resources into a couple key cards, but those cards still have to leave the stack for them to win. The more you leave pieces in play, the more your opponent can miss the small stack window to interact with them and still be able to find an answer.

There is also an investment portion to vulnerability. If they kill one half of your combo, but the other one sits in play, it’s a lot easier to win than if they stop one card in which you have invested a large number of other cards. Compare an Exhume being countered with a Deceiver Exarch dying in response to Splinter Twin or an Infernal Tutor being countered. In the first scenario, Reanimator needs to draw one card to win. In the others, the combo player is down two or all of their cards and has to find a way to recover.

Kinds of Combo:

In practice, combo tends to blend between two distinct subarchetypes that function fairly differently. This is similar to how a Red deck and a White Weenie deck both are trying to exchange their cards for the maximum amount of damage but do so in very different ways.

The first main category is multi-card combo. You assemble a couple specific cards, and your opponent loses the game. Examples are Splinter Twin–Deceiver Exarch, Aluren–Imperial Recruiter, Entomb-Reanimation Spell, Donate–Illusions of Grandeur, etc. Their kill turn is often highly variable depending on how much time you spend tutoring for your specific kill cards in a given game. There is around a 15% chance you just have both halves of a two card combo in your opening seven and just kill them, but the rest of the time you have to do some work. Redundancy is much more important than velocity in these decks, as often you are looking for one specific card from the get go and the other forty cards in your deck are blank. Tutors are much better here as they always hit the one card you need, and tutors that cost cards over mana are stronger, as you only need two cards to win not counting disruption.

Typically, two-card combo decks are much better than higher card count combos as they are significantly easier to assemble. The odds of having a three-card combo in your opening hand are under half the odds of having a two-card combo. On rare occasions there exists a one-card combo such as Enduring Ideal or Tooth and Nail, but most often those have their own limitations.

Most notable is the number of auxiliary cards associated with them as well as the fact that the one-card combo typically is some expensive spell that needs a large amount of acceleration to be used in a relevant time frame. Cantrips are also much better in one-card combo decks, as you know from the start exactly what you are looking for instead of having to find two different things.

Two-card combos can start to approach a one-card combo if you have enough redundant copies of one of the pieces. Hive Mind does this very well, with eleven Pacts making it easy just to randomly have or run into one even while just using cantrips to find your other cards.

From there, you have another archetype. There isn’t a great name for it, but I’ve been referring to it as full deck combo. This is Storm, High Tide, Elves, or Dredge. You might have a couple of card pairs that are very good together, but mostly your deck is a large number of interchangeable pieces that turn into a win. You are typically a lot less varied in terms of how fast you kill, which is good and bad.

On one hand it means that you are more likely to beat a deck that is inherently slower than you, but you also have to accept that faster combo decks are going to be hard to mise against, and you will have to try and disrupt them. A good example of this is Reanimator in combo mirrors. Reanimator has a fundamental turn much closer to two in combo mirrors than most other decks due to Jin-Gitaxias and Iona. A large chunk of the time, an opposing Elves or Storm player is completely out of the game before they were even close to getting in it, regardless of the fact Reanimator is more disruption dense.

Full combo decks range widely as to whether velocity or redundancy is a better approach. Typically I have found that because your pieces aren’t quite as unique and you are more about setting up the perfect hand, cantrips are much better. However most of the time they aren’t an option, as they don’t synergize with your deck well. If you are generating a hundred blue mana or trying to hit ten spells, they are great, but when you are trying to cast a bunch of one-mana creatures or hit exactly seven mana to play and activate Goblin Charbelcher, they won’t do you much good.

One thing to note is that almost every deck with a fundamental turn of one outside of Vintage has been redundancy-based full deck combo. Simply put, if you are going to win on turn one, you don’t have time to cast tutors or cantrips. You need the cards you are going to win with now, not next turn.

They are also some of the most fragile combo decks, as the game does not actually get much better for them with every passing turn. Whereas other decks can cash in a turn of mana to find exactly what gets them out of the situation they are in.

Disruption:

Not everyone is a goldfish. Most or some decks will try to interact with you, and you need a plan for when they do.

The first consideration with disruption is if you can actually afford it. If you have no reasonable way of finding your interaction when you need it and you have to make your deck significantly less consistent to play it, you are probably going to lose more games to having to mulligan or drawing blanks than you will by answering their answers.

Prime examples of this are Belcher and Dredge. Unless you think your opponent is 100% going to mulligan for their Force of Will or Leyline of the Void and you have actually no way to beat it if they have it, you are probably better off just playing the linear game and catching them when they don’t have it. Specifically with Dredge, even with mulligans, you have reasonable odds they will miss it either game two or three or that they won’t even have it in their deck.

Another good example is the one maindeck Chain of Vapor some non-Grim Tutor UB Storm decks play. Even if they have maindeck Gaddock Teeg or something similar, the only way you have to really dig for it is Ad Nauseam, which is not going to be castable. Having the miser out is worse than just winning the other games or winning before they cast Teeg. Even if your deck has good card filtering or tutoring, you have to determine how many core slots are required to maintain consistency. If you start playing a bunch of disruption over combo cards, you can slow yourself down and make your deck vulnerable to fair things like Lightning Bolt. This is why Wishes are so strong, as not only are they tutors for combo pieces, but they can find random answers without you having to draw those cards when they would be blanks.

Next is figuring out which card you want. A lot of this has to do with what cards you need to beat, but some of it is also cost limited. For example, Hive Mind wants to beat Daze and Stifle, so it would love Thoughtseize or Vendilion Clique. The problem with those is that it doesn’t necessarily have the time to pay for a spell and also needs to stop things like Hymn to Tourach, so Force of Will is a common choice. Lion’s Eye Diamond decks can’t protect their Tutors with Forces and still use their Black Lotus, so they go to preemptive methods like Duress and Xantid Swarm. Splinter Twin has to beat cheap, instant-speed removal, Spellskite, and people racing it, so it looks to Dispel and a mixed removal base.

There is also a huge distinction between main deck and sideboard disruption due to hate cards. People are unlikely to play something like Sundial of the Infinite main, but post-board Hive Mind has to watch for it. A main deck bounce spell would make no sense, but depending on what people are sideboarding, it might be correct in your fifteen.

An important thing to look for is cards that provide overlapping answers to their hate without being inefficient so that you don’t end up with dead cards if you guess wrong as to what they have. Chain of Vapor in Storm is the dream card here, not only being the cheapest bounce spell printed but also providing extra Storm by bouncing mana artifacts even if it is dead. It can even just bounce a creature to buy a turn.

Compare that to Echoing Truth, which is less flexible and costs more but can stop multiple copies of a card or a Chalice of the Void set at one. Most of the time you see the former in sideboards and only sometimes the latter.

The more flexible card that provides utility when you don’t line it up with their card is the default, with the burden of proof being on the less flexible card. Other examples of this are Chalice of the Void to answer Angel’s Grace or Winds of Change out of Dredge to beat faster combo decks. Splinter Twin in Standard is in the fortunate position of facing down a lot of creature-based hate, allowing it to lean on useful removal to answer their answers.

The Mana:

The most important thing is to make sure it works to begin with. If you are losing games to not finding colored mana, that is just one more thing to worry about finding in order to win. Having the right mana ideally should be a non-issue.

From there, you need to figure out how to hit your key counts for specific cards on time. Even with minor changes, things can be different. For example the curve of Lim-Dul’s Vault into Show and Tell is completely different from Intuition into Show and Tell. The former is easy off normal lands, while the latter wants you to play a large number of double mana lands like Ancient Tomb to cast one of the spells on turn two and still be able to play the second on turn three through a Wasteland. Just figuring out whether you want to Ponder or Duress on one can mean two different mana bases.

On a Legacy specific note, understand Wasteland. If you can’t curve out ideally against the card, things may need to be reconsidered. Ideally you will either have all basics or fetchlands to blank the card until the turn you win or will be able to ignore the land loss moving forward. I’ve found Daze makes the latter risky in certain decks, but others like the aforementioned Intuition–Show and Tell decks can afford to not care, especially as Daze is better off saved against them a large chunk of the time.

Beyond Building:

Each combo deck is going to function in different ways. Even something as simple as when you cast a Duress can vary drastically depending on deck.

If you have specific questions about a given combo deck, primers for a lot of them are out there. Depending on how prominent the deck is, they can range in detail, but I’ve found that combo primers tend to be very specific—if only because the majority of variable situations most decks have to contend with due to combat are ones you can just ignore. If you can’t find them, feel free to ask me in the feedback section here or @armlx on Twitter, and I’ll do my best to answer to try and direct you to someone who would know better.

–Ari Lax