Sideboard: How to Build it & How to Use it

Sideboard is one of the most important elements of competitive Magic. After all, it's with its cards that many games take totally unexpected turns and matches are defined based on the outcome of the pieces you include from it and remove from your maindeck.

It's been a long time since I've had the idea of ​​working on the concepts behind building a Sideboard and how to improve your choices for the limited space it has.

If you are just starting to play Magic: The Gathering, or are used to playing only Best of 1 in Magic Arena, the Sideboard is a combination of up to 15 cards that are separate from your maindeck (usually, with 60 cards).

You can exchange cards from your Maindeck for cards from your Sideboard between games 2 and 3 of the Best of 3 matches, which is the primary mode of tabletop tournaments in basically every competitive events. The purpose of Sideboard is essentially to improve your game against your opponents by removing the bad cards against their deck in exchange for better options that are available from those 15 cards — thus increasing your odds of winning the next games.

Although you can play with more than 60 cards in your Maindeck, you cannot have more than 15 cards in your Sideboard after completing the process. That is, you cannot remove something from your Maindeck without putting something from the Sideboard in its place.

This is the simple part to explain in terms of Sideboard, but let's go now to what really matters and, commonly, it causes a lot of difficulty for less experienced players and/or those who are less used to deckbuilding and competitive games.

The realistic answer is: it depends.

Although Magic follows different patterns and some strategies coexist in very similar ways in the game, there are many nuances that differentiate the way we build our Sideboard: the Metagame of the format your deck fits in, available card options, the way you chose to build your list, main archetypes from the competitive landscape or from your region, among a multitude of other circumstances which will constantly change in your journey through the game.

Also, your Maindeck and Sideboard shouldn't specifically be treated as separate things: slots between one and the other can be complementary, and the Sideboard basically operates as an extension of your Maindeck in many occasions.

However, we can follow some general guidelines based on the game's history to define what normally goes into the Sideboard.

Answers that normally don't fit the Maindeck

There are several cards in the game that are very useful in responding to specific situations, but not so common in a normal Magic matchup that they deserve a maindeck slot because they might be dead cards in your hand more often than you wish for.

Disenchant, for example, is very useful if your opponent has some enchantment that gets in the way of your game plan or if their strategy depends on one artifact or too many artifacts on the battlefield to work. But against a Mono Red Aggro geared towards attacking with multiple creatures and dealing direct damage with Lightning Bolt, you're hardly going to have any use for it — even if Mono Red happens to be running Kumano Faces Kakkazan or Bomat Courier.

Likewise, you'll hardly want a graveyard hate like Rest in Peace in Maindeck because it'll rarely do anything relevant in a regular game, unless you're trying to combo with Helm of Obedience.

While Pithing Needle, despite normally having legal targets in many games, is too specific an answer to deal with problematic abilities like those of a Planeswalker, or a combo piece like the one mentioned above Helm of Obedience where actually the opponent would want something like a Disenchant to deal with your Pithing Needle.

There are some spells that are commonly found on the Sideboard, but that may belong to the Maindeck if the current format scenario makes it possible, since they have much more flexible abilities than specific cards.

Duress and Negate are classic examples in Standard, where many decks resort to non-creature spells, making it possible to include one or two copies of them for a strategic advantage in Game 1, as well as opening up more slots in the limited space of 15 cards on the Sideboard.

We also see this situation where Sideboard cards enter the Maindeck when there is a predominant archetype in the Metagame with a natural weakness to specific hate, or when many decks have the same theme to work — The most recent example is in Pauper, where the Affinity is the current best deck in the format, and several other strategies has artifacts like Experimental Synthesizer or Bridges (being artifact-lands, like Silverbluff Bridge), significantly expanding the usefulness of a 2-for-1 against Artifacts like Dust to Dust.

Another example of cards that are commonly found on the Sideboard are the so-called “color hosers” — answers to specific colors, such as Pyroblast and Hydroblast, which only work on red and blue spells.

Sometimes we can also add color hosers to the Maindeck as the Metagame demands, especially if they come coupled with some additional utility, as with Burning Hands and Ray of Enfeeblement, which still work as weak removals or combat trick while being very efficient against white or green creatures.

In recent years, Wizards has increased the answers' flexibility to fit them in more than one situation, increasing the complexity of Sideboard inclusions and also opening space for many of them to appear in the Maindeck in the most varied formats.

Abrade, for example, was featured on many lists in Standard for dealing with Esika's Chariot while also functioning as a removal. Suffocating Fumes spawns in the maindeck of many Pauper archetypes because, in addition to killing small creatures like Battle Screech tokens, it will never be a dead card in your hand as you can always cycle it to get a new draw, and Unlicensed Hearse has become a staple in many formats for being a mighty graveyard hoser that also becomes a win condition if the game drags on too much.

The Targeted Lock Pieces

Finally, another common element on Sideboards are spells that, while very specific, delay or simply destroy the opponent's ability to execute their plan as expected.

Blood Moon, for example, is very problematic for lists with a greedy manabase and full of non-basic lands with no means of being able to play around it, while Chalice of the Void punishes any archetype that has an abundance of spells with a specific cost of 1 or 2, forcing the opponent to deal with those permanents first before proceeding with their original plan.

Permanent graveyard hosers, such as Rest in Peace, also fall into this category if you face an opponent with a fully graveyard-oriented strategy.

Answers to Answers

If your strategy is to play with multiple creatures, populate the board, and attack quickly, your opponent will likely include sweepers like Anger of the Gods to deal with them before it's too late. In that case, you want Selfless Spirit to protect your creatures when they try to remove them, or maybe something like Elite Spellbinder to delay them for two turns — long enough for your creatures to finish the job.

Likewise, if you're playing with a combo like Storm, which is looking to cast multiple spells in one turn and win with a gigantic Grapeshot, Echoing Truth or other removal will be necessary to deal with the Deafening Silence or Archon of Emeria on the other side before you can start your streak.

Gameplan Adaptations

Let's say your deck is an Aggro filled with fast creatures and your opponent, a Midrange, will put in some sweepers that deal with it without hurting them too much since they rely on bigger creatures, making it difficult for you to win the Game 2 quickly, and they will easily have the upper hand since their cards get better as the game goes on.

To stay in the game, you'll have to trade speed for value, and for that, you need to remove your creatures that don't create any additional value and are easily answered by the opponent in exchange for permanents that allow you to extend the game— in this case, you put Chandra, Torch of Defiance which, despite costing four mana and being above your average curve, offers removal, card advantage, and a long-term clock against your opponent. Additionally, you can choose to add other cards that generate 2-for-1 effects, such as Glorybringer, or that are difficult to remove from the board, such as Hazoret the Fervent.

By adding these cards, your list becomes less explosive, but you adapt to the play style your opponent proposes, in addition to making the Cry of the Carnarium they added on the post-side a worse top deck.

Having cards on the Sideboard to adapt your deck to a specific game or even catch an opponent off guard is a valid and common option in competitive Magic.

One of my favorite examples occurred in Pioneer, when Dimir Inverter (focused on the combo between Inverter of Truth and Thassa's Oracle) added Pack Rat to the sideboard to deal with very disruptive strategies that relied exclusively on disrupting the combo.

Pack Rat, in this case, added value to the alternative plan of playing as a Control or Midrange in interactive games, as a hard to deal with threat without sweepers and that easily went out of control if the opponent bet on 1-for-1 trades.

Read the Metagame

The first point to build your Sideboard is to understand the format you are playing: What are the best decks? What are the most popular archetypes in the general Metagame or in your local store? What do you expect to face? Which ones are your bad matchups?

With the advent of the Internet and social media, most of this information is easy to access with a little Google search or a quick question on somewhere like Reddit, but it's always good to look for multiple information sources about your deck and the format, in addition to doing your own research in relation to the scenario of your region/or store.

Define the best options available

Pioneer's current best deck at the time of writing this article is Mono Green Devotion, and you're playing Rakdos Midrange, which means having a relevant amount of answers for this matchup.

But which card among these are really important for the course of the game? Burning Hands sure doesn't work as well as Noxious Grasp against Mono-Green, but it is more flexible in a slot for creature matchups.

However, you want to avoid the risk of your removal not being enough to deal with something the opponent does, so Noxious Grasp is probably a better option.

But what if you want to have a complementary threat that pairs well with Fable of the Mirror-Breaker? In this case, Lifebane Zombie isn't more interesting? Or is the fact that it only removes creatures from the opponent's hand a serious problem when we need to respond to Planeswalkers and deal with Storm the Festival?

The point is, you need to know the options available and understand where each of them best performs the desired function. And this will usually come with a lot of testing, training, communication with other players and a lot of reading and accessing content regarding your deck, which brings us to the third point:

Search and analyze other decklists

In the digitized world where information circulates quickly, there is no longer so much exploration and “secret techs” in Magic. We created a sort of "hive mind" as everyone seeks to improve their decks to put them at the top of the format and win tournaments.

Because of this, Metagame pages are essential (and we have one here at Cards Realm), and you should access them to research how other players are building the same list that you are piloting and, if you have any doubts about a card on the maindeck or sideboard, you can always test it yourself on some free platform, or by printing it on a piece of paper and putting it on top of another card inside a sleeve, to understand its usefulness.

Again following the example of Rakdos Midrange on Pioneer, there have been lists running Invoke Despair on the Maindeck or Sideboard in recent weeks. Since a five mana sorcery is a relatively high cost for a Midrange in this format, it might not seem very intuitive to some players why it started to make an appearance, but once you cast it in the right game, the 3-for -1 provided by it starts to make more sense.

And don't forget to also analyze what your opponents have against you, and how their Sideboard cards can affect your strategy.

Don't spend slots on matchups you cannot win.

If a matchup is really bad for your deck, dedicating several slots on your Sideboard to it won't improve it unless you have a good winrate against the rest of the Metagame, which usually only happens when you are piloting a broken deck.

The classic example of this situation is in Pauper, where Mono-Black Devotion has an abysmally bad match against Burn, with a winrate of around 20-25%. In other words, it's a game where Mono-Black only wins if they get lucky and/or if Burn's pilot commits countless misplays.

Post-Sideboard Mono-Black has many dead cards — Sign in Blood, Snuff Out and Phyrexian Rager interact negatively with this match where your life total is the element that matters most — and there was a time when players would try to add specific options to deal with this matchup, like Pharika's Cure, Sovereign's Bite or Syphon Life, lifegain cards to delay Burn long enough to cast Gray Merchant of Asphodel.

But attempting to gain life from Mono-Black against Burn was postponing the inevitable: you'd lose the game faster than you could recover, and the four copies of lifegain you added wouldn't be enough to prevent that, so you were losing four or more slots on your Sideboard trying to make a horrible matchup less horrible, and the price was never worth it because it meant making your game worse against the rest of the format: there were fewer Shrivels against Faeries, less Diabolic Edicts against Bogles, fewer Wrench Minds against the Mirror, etc.

Your slots would be better used if you, instead of adding Lifegain, were looking to improve other games and/or choose more comprehensive options like Duress or Distress, which worked very well against slower games and could give you an “extra turn” when removing Fireblast or another damage spell like Searing Blaze, that would kill your Chittering Rats and make you gain 2 less life with Gray Merchant of Asphodel, or Unexpected Fangs, which also works against other Aggro decks, being particularly lethal alongside Gurmag Angler.

And speaking of flexible options...

Prioritize flexibility

The Sideboard is an extremely limited space, and it definitely won't have everything we want in its few slots, so we have to define what we need, in addition to looking to extend the usefulness of our choices.

I have a general rule that the more situational the card is, the more dependent it is on a specific Metagame and the less useful it is in a large tournament, unless there is a very popular strategy that demands linear answers.

For example, suppose an imaginary situation where you play in a Modern setting where there are artifact-centric archetypes, and you are playing with a list like Izzet Murktide, which has multiple cantrips like Consider and additional draws with Ledger Shredder and to respond to this interaction with artifacts, you have to choose between Shenanigans or Abrade.

In this case, we need to assess the predominance of artifacts in the Metagame, how good or bad our game is against it, and how relevant both pieces are outside that particular game.

In a typical situation, I would normally opt for Abrade over Shenanigans if this artifact deck wasn't so prevalent because it's also a side-in that I can add against creature archetypes where my Counterspells or more situational cards like Spell Pierce are less useful, while Shenanigans works incredibly better for this particular matchup, but is a poor option or absolutely nil against the other decks.

On the other hand, if the artifact deck is very present and/or other strategies seek to take advantage of interactions with artifacts for some reason, Shenanigans is most likely a better option than Abrade, as it gives me the same advantage against other archetypes at that time.

When you're building your Sideboard, consider not just how much a card can help you in a particular game, but also what other games it's useful for — A Noxious Grasp is great against Mono Green Devotion in Pioneer, but also It serves some purpose in dealing with Azorius Control's Planeswalkers, or as an extra removal against Humans, while something more specific that only dealt with green creatures wouldn't have the same flexibility.

However, going back to the example between Abrade and Shenanigans, if I were playing with Izzet Murktide or any other archetype with a large number of cantrips and/or that manages to access numerous cards over the course of the game, I would split 1 copy of each on my Sideboard, leading us to the next question:

I truly believe that this question requires a more in-depth article of its own on how to make certain numerical decisions in Sideboard, which I intend to provide in the future, but I suppose we can exemplify some general lines.

Decks like Izzet Murktide, which have many cantrips and card selection, or archetypes like Rakdos Midrange, which accumulate a lot of card advantage in the long run can diversify their sideboard better than a list with little access to draws or cantrips, like a Boros Burn or Mono-Red Aggro, that will normally need three or more copies of the most important cards and around two of the less important ones.

As an example, during the Crimson Vow and Neon Dynasty season, my Izzet Phoenix tabletop decklist had three copies of Aether Gust (as Naya Winota, Mono Red and Izzet Phoenix were very popular), two copies of Mystical Dispute (as they were useful against Midrange and Control), and the rest of my Sideboard was made up of a copy of each card, something that was also present in my Maindeck: all my removals were singleton (except for Lightning Axe, which was a 2-of), my Delve Spells were diversified into one copy of each, my complementary threats were a Brazen Borrower and a Crackling Drake — that's because between Expressive Iteration, Consider, Pieces of the Puzzle, Treasure Cruise and Dig Through Time (not to mention the potential to copy them with Galvanic Iteration), I had all the necessary means to virtually have access to almost every card on my list.

But another element that needs to be considered when defining the number of copies of each card is the predominance of games in which these spells really matter: at times, I had four Aether Gust on the Sideboard as the number of green and red decks increased or decreased each week, and so did Mystical Dispute as the presence of Midrange or Blue-Based decks increased.

This effect is something we've seen when an archetype is too oppressive or too prevalent in the format as well: when Hogaak, Arisen Necropolis completely broke Modern, it was normal to see players adding four copies of Leyline of the Void, plus additional options like Relic of Progenitus just to have more chances against it.

Evaluating in a general context, I usually start my Sideboard with two copies of each card, and a third copy of the more comprehensive option, and from my tests and games, I start to evaluate what can go in or out, or what I can increase or reduce numbers as needed.

Finally, now that your Sideboard is built, you need to understand how to optimize your choices.

Consider who is on the Play or Draw

The definition of who starts first increases or decreases the value of certain cards in the game. Low-cost removals like Lightning Bolt and Fatal Push, for example, are better on the draw as they help recover the negative tempo of not making the first land drop, while fast threats like Robber of the Rich or higher cost permission spells like Counterspell tend to be better on the play because you get more value out of them when you're not behind.

Having this awareness can significantly change the way you choose the cards that go in and out between Games 2 and 3, and even influence your posture.

Identify the posture to be taken

You ended Game 1. Whether you were victorious or not, you took a certain stance with your plays and needed to follow a certain line of reasoning.

When choosing what to add or remove, first consider how you will need to behave in upcoming games: will you need to be the beatdown or the control? Do you have to bet on speed or value to guarantee your victory? What will be the best way to use your resources? Does your opponent's deck fall into which macro-archetype category? How do you usually need to behave in this match, and what are your advantages and disadvantages in relation to your opponent?

By identifying these points and understanding your posture, you will broaden your options and optimize your choices.

Assess what can be used against you

You're not the only one with a Sideboard, and your opponent also has tools against you, and knowing what their options are will also help you decide what goes in or out.

If there will be more removals, you want either hard to kill threats or creatures with an immediate impact and/or discards and counterspells to protect them.

Or if they have some specific hate like Rest in Peace, you get to play around (or even change your game plan to "counter" it), or do you need to deal with those cards to execute your combo or explosive plays that will lead you to victory?

Understanding which options are likely to enter from the other side of the table and knowing how and when you need to respond appropriately to them will help you not only choose your Sideboard cards, but also understand what posture you should have.

Consider which cards contribute to the execution of your game plan

“Okay, but what goes in or out?”

Well, everything in Magic can be answered with “it depends”, including what to add or remove in Games 2 and 3.

Considering your opponent's strategy, which cards are least useful? If it's a Control, there's no reason for you to keep removals like Fatal Push because they'll rarely be useful, even if they resort to manlands like Celestial Colonnade, so removing them makes room for better options like maybe Duress or extra attrition like a creature that can't be countered or that has built-in protection.

Likewise, permission spells like Counterspell or targeted discards like Thoughtseize are less relevant against fast decks like a Mono-Red Aggro, and you'd rather have more low-cost removals, or more sweepers to deal with more than one creature at a time.

Fast creatures like Goblin Guide are excellent ways to start the game, but they are of little relevance if your opponent's turn 2 involves a larger creature like Tarmogoyf, which easily blocks it if your proposal doesn't involve spending a Lightning Bolt to keep attacking. In that case, removing it for late-game pieces or means of getting more reach is an option.

Don't put too many cards in

It's possible that up to fifteen cards from your Sideboard are useful against some specific archetypes, but that doesn't mean having to remove fifteen cards from the maindeck to add them all - that will significantly hinder your strategy, leaving you too reactive while you fail miserably at do what you set out to do.

This rule varies a lot from one macro-archetype to another: Combo Decks tend to be much less flexible in the Sideboard sense, especially those that need multiple pieces to work like Storm. Aggro decks don't want to add as many pieces either, unless the game plan involves getting closer to the Midrange spectrum, which tends to be more flexible with what can go in or out of the maindeck and sideboard, while Control is almost completely flexible regarding its slots as you usually have more useless cards between one game and another in the Maindeck — even being able to change to a more aggressive posture in some games with few copies of cheap threats like Adanto Vanguard, or creatures that generate long-term value, like Thief of Sanity.

My rule is that if my Side-In includes more than 6-8 cards and my Side-Out doesn't have as many obvious things to remove (like Sign in Blood and Phyrexian Rager versus Burn), I reevaluate how much I really need the cards I want to put in and why I need them.

Write down your choices and reconsider later

Every living being on the planet makes mistakes, it's inevitable — but we need to learn from them.

As you play your games, try to keep track of what went in and out between the Maindeck and Sideboard and then re-evaluate how those decisions impacted the game and what you could change about those choices. Do this with every game you play, and before long, you'll have built your own Sideboard guide, which you can always refer to and share elsewhere for an overall improvement to your decisions and the community as a whole.

By the end of this article, I hope I've helped you better understand the nature of a Sideboard and how to build and use it efficiently. There are many topics I haven't gotten into or delved into that deserve their own articles, and at some point I plan to bring them to the public.

If you're interested, I also made a article about five common deckbuilding mistakes that players often make.

If you have any questions or suggestions, feel free to leave them in the comments.

Thanks for reading!