Theros Beyond Death available now
   Sign In
Create Account

Building Sideboards In Legacy



The sideboard is the most versatile and customizable part of any deck, because of which it is also the easiest place to falter. Sideboards can be invaluable to the deck while running through a tournament, or essentially worthless if done improperly. When I was tweaking for Standard just before the Caw-Blade dominance, I was looking at all of the available options for sideboards in Standard, and there weren’t many options, so it wasn’t as easy to ruin your sideboard. A given deck seldom had many changes in the fifteen cards in the side when compared to any other decks of the same archetype, because sideboards seemed to easily make themselves with what was available, but, there were still times when people were following the wrong beat to accomplish effective sideboarding. Today, I’ll be focusing on how to get the most from your sideboard in Legacy, but giving general tips that can be applied to other formats as well.

What a Sideboard Should Do

The first step to making a successful sideboard is to have an intricate understanding of how the deck you’re playing operates. Specifically, you should be trying to address what the weak matches are and what the reasons for those weaknesses are. Simply put, your sideboard’s job is to help you smooth out as many problematic matches as possible. There are several ways to approach this goal, and because you can never fully anticipate a metagame, there is a margin for error, exactly the same way as there is with deck choice, meaning that like everything in Legacy, the optimal choice is not always the correct choice—but that is no excuse to get sloppy. I think that these are the best ways to look at including cards for your sideboard:

1. Use cards that attack entire strategies, not just decks.

There are a lot of times where people will ask me about a sideboard choice, and I’ll ask them what it’s for, and they respond with a short list of specific decks. That’s when I learn how often these players are trying to address problem matches of somewhat niche decks. The numbers for Goblins in a given metagame are relatively small, and so it would generally be a waste of space to include copies of Tivadar's Crusade in your sideboard, as it’s only truly effective against one deck. (This isn’t so much true with Merfolk, making up 10% to 20% of any given metagame; Merfolk is the exception to this and worth attacking as a deck even if the cards you use for it don’t really hit any other strategies, such as Peacekeeper or Llawan, Cephalid Empress.) However, if you’re in a position where you’re dedicating most of your sideboard to attack a specific deck, unless you both objectively and undeniably crush every other deck, you should probably just be looking at playing a different deck, because a sideboard dedicated to beating something simply never works out.

Cards that I feel are really strong inclusions are akin to Tormod's Crypt and Relic of Progenitus; both are staples and attack nearly all graveyard strategies, without being weak to any one in specific, like Leyline of the Void, Loaming Shaman, or Surgical Extraction would be. The best sideboarding inclusions are effects that punish multiple strategies like Blood Moon and Back to Basics, and great utility cards such as Path to Exile, Dismember, Submerge, Krosan Grip, Pithing Needle, Phyrexian Revoker, and many other cards that don’t ever attack a specific deck but handle problematic permanents with few if any restrictions. While these cards may not be in every board, these cards offer such a depth of versatility that it’s worthwhile to consider if these cards are able to answer the problems you face without resorting to narrower cards, even if the narrower cards are often more powerful for the specific threat you have in mind.

2. Focus on the matches you can win.

When I was playing Landstill, by far my worst matches were Burn and Dredge, and both were outside the realm of winning if I still wanted to have a game against other decks. Because I was playing Cunning Wish, my board was a bit different, but I gave each of these decks a single card to fight them: Pulse of the Fields, which had some use against aggro decks, and Ravenous Trap, which was pretty narrow but was my only chance against Dredge. Beyond those cards, it wasn’t worth it to sacrifice cards for matches that I could actually turn in my favor post-board to attack two fringe decks that I likely would not be able to beat even with sideboard cards. Going back to the first point: If you have to be able to beat a certain deck and you know it, you don’t play the deck that you’re trying to sideboard for, you play a different deck and allow yourself room to breathe with the board slots that you free up.

One of the most important uses of your sideboard is going to be to fight the close games, by using your own board trumps to the sideboard cards that your opponent may use or by having answers for the problems he presents you. If you are playing a deck that’s weak to Emrakul, is it really worth it to stick in a Karakas or Phyrexian Metamorph to try to answer it when you consider that the cards have almost no value aside from that? I think it’s better to just try to execute your game plan the most efficient way possible and try to attack the opponent in ways that don’t count on him executing his game perfectly until you surprise him with your tricky Phyrexian Metamorph. What if the opponent put in Form of the Dragon off Show and Tell or is actually playing Hive Mind—how good is Phyrexian Metamorph then? If you’re playing Zoo or some other deck that has no chance against Hive Mind or another Show and Tell deck, why waste the slots on cards that are going to derail your deck’s strategy in hopes of minimally disrupting the opponent?

3. Sideboard cards actually need to be exchanged for cards in the main.

A common problem, especially with newer players to a format, is dedicating too many sideboard slots to some problem matches without considering what is going to be boarded out when the time comes. I highly suggest that you come up with board strategies for common matches that focus on optimizing the potency of the cards you have available to you and write them down. If you oversideboard, you run the risk of having too many answers and not enough threats, which is often worse than just not having a board, because it allows an opponent time to build up resources and overcome during a time you were supposed to be applying pressure. Thanks to a somewhat recent change in the Magic Tournament Rules (Section 2.9 “Taking Notes”), you can actually reference a page or two of sideboarding notes between games to make sure that you get your sideboard right. No excuses.

4. If boarding to beat hate cards, make sure your cards actually foil them.

Recently, I’ve been experimenting with Reanimator. There are a lot of sideboard options to pick for the deck, and a lot of ways to get it wrong. At first, I was using Null Rod, as it was effective in several matches as a silver bullet and it turned off most graveyard hate, but it wasn’t able to address some problems such as Leyline of the Void. After getting my Show and Tells back from a friend, I realized that the missing piece to the sideboard was Show and Tell; there was no real need for bounce or Null Rods if I was able to just bypass all graveyard hate with Show and Tell. That allowed me to use my Null Rod slots to address boarder problems with Pithing Needle and use my bounce spells to play other disruption spells such as Thoughtseize and a couple of creatures I couldn’t cram into the main, These changes to the board immediately impacted the strength of the matches I had, giving me much broader reach to fight decks.

What Sideboards Shouldn’t Do

1. The sideboard shouldn’t be the only way you can beat a deck you need to beat.

Obviously, you’ll need to beat any deck you’re playing against, but that is the power of foresight. If you’re playing a deck that is incredibly weak to a common archetype—Merfolk, for example—make sure that your only realistic chance of beating the deck doesn’t lie in your sideboard. If you can, make changes to the main that aren’t going to totally compromise the integrity of the deck, or, as I suggested before, try another deck. For local events, where the metagame is generally a known quantity, this is a lot easier; be sure never to leave yourself cold to someone who always does well if you intend to do well. If you’re going to play in the tournament, you may as well give winning a chance.

2. Sideboards shouldn’t change the overall strategy of your deck.

If you’re playing an aggro deck or a control deck, you want to be sure that you’re still playing that role after sideboarding unless you have a really great trick up your sleeve. I’ll talk a bit later about a Zoo deck that tries to play control against control and combo decks; the reason that these sideboard plan strategies are so flawed is that even if you have fifteen sideboard cards dedicated to changing roles, you still have roughly thirty-six spells in the main that are probably putting you in one direction or another. Of course, there is some leeway with aggro-control decks, but at the same time, if you don’t correctly identify your role in the match, you’re liable to play yourself out of the game. To generalize: Proactive decks should be playing proactive cards. Reactive decks should be playing reactive cards. Make sure every card in your seventy-five is working toward the same end as much as possible.

3. A sideboard isn’t a good home for cards you know should be in your main deck.

If you know that you need to be paying something in the main, find space for it. There is almost no reason to forgo playing potent, versatile cards in the main if at all possible. Starting with Force of Will in the side is a cute trick that a few people have gotten away with, but they have essentially wasted board slots that can’t be used against their problem matches, generally aggro and combo decks. Just because someone else was able to get coverage with a deck doesn’t mean it was a good choice. Your goal in a tournament should always be to improve and have the most solid lists you possibly can; otherwise, the major reason to enter a tournament is outside of your grasp.

Case Studies


I was working with a friend, and he asked me for some help with his U/G/W Aggro-Slivers sideboard. I took a look at it, and this is close to what I saw:

My first question was, “Why is Daze in the board?” to which he explained that Daze is only good on the play, and so he only wanted to board it in when he knew that he was going to be playing first—that is, any time he lost a game. I then asked him what he wanted to board in the other cards for, which a bit more direct: Spell Pierce was coming in against control and combo, Meddling Mage was coming in against control and combo, Daze was always coming in against control and combo, and Krosan Grip was for control. After this, I reached the conclusion that he wanted to board in thirteen of his fifteen total sideboard cards against control and eleven against combo. So where do you start taking cards out against those decks?

−4 Swords to Plowshares

−4 Sidewinder Sliver

−3 Winged Sliver

That’s eleven cards to take out against Combo decks, leaving him with fifteen creatures, all of which are at 2 power—and, of course, none of them are very good on their own. The only potent cards he’s bringing in are really Spell Pierce and Meddling Mage. Against control, the cuts are even more difficult, because a deck like this needs a high creature density if it’s going to hope to win at all. The biggest problem with his board is that when it came to real problem matches such as Merfolk and Zoo, he had basically nothing. Working with him through this wasn’t easy; there were some cards he was hesitant to budge on, but after a lot of prodding and questioning, we finally agreed that you either play the Daze in the main or don’t play it at all. He also realized that he had far too many cards for matches that he maybe didn’t need that many cards to help address. While the sideboard that he settled on wasn’t perfect, it was a far stretch better than what he was originally working with:

4 Spell Pierce

3 Relic of Progenitus

3 Submerge

3 Harmonic Sliver

2 Llawan, Cephalid Empress

This set of changes gave him tools to fight some of the common and problematic decks without ever needing to dilute his deck to a point of inconsistency. There’s still a lot of room for growth in this list, but it’s a process to learn what sideboard strategies are effective, and he’s making progress with this one.


When researching decks, especially in Legacy, you’ll sometimes be presented with two sideboards for decks that have nearly identical sixties, but have sideboards that suggest two entirely different decks. Take, for example, these Zoo sideboards:

List 1

2 Ethersworn Canonist

1 Bojuka Bog

1 Gaddock Teeg

2 Krosan Grip

2 Choke

2 Null Rod

2 Enlightened Tutor

2 Tormod's Crypt

1 Serenity

List 2

3 Choke

3 Krosan Grip

2 Red Elemental Blast

1 Nihil Spellbomb

1 Tormod's Crypt

1 Gaddock Teeg

4 Reverent Silence

List 3

2 Red Elemental Blast

4 Pyroblast

4 Mental Misstep

2 Krosan Grip

1 Gaddock Teeg

2 Path to Exile

Take another look over these lists. These sideboards all come from lists that play Green Sun's Zenith and a single Gaddock Teeg in the main deck, and are all fairly standard Zoo lists that have made the Top 8 in an event. Which board do you like most?

I like the first board a lot because it has ease of access to potent cards that are going to have huge impacts on a game. The Enlightened Tutor package in Zoo decks has become increasingly popular since New Phyrexia, and it offers consistent access to numerous potent answers such as Choke, Serenity, and Null Rod, all of which will often win against the deck in question if resolved. The cost for this flexibility comes at the price of a card, but considering that these cards will swing the game heavily in your favor, I think it’s a worthwhile trade.

The other decks are using sideboards that are loaded up to beat unknown factors and are probably using the board slots they have inefficiently, overloading the board with cards that probably aren’t even addressing the problem matches the best they could. Compare how the lists are planning on boarding against Landstill variants or a Storm deck. What about Merfolk—how much boarding does Zoo need to do there? Even for the decks against which you want these sorts of cards, there isn’t room to board out more than six or so cards in a given match when you’re playing Zoo, and some choices in these sideboards reflect a rather poor understanding of how the deck functions in the metagame, which is important. Zoo isn’t playing the control deck in any match where it’s boarding in these cards, so most everything you’re playing should be a threat—a deal-with-it-or-lose threat. What about the deck you’re playing—what roles does your deck play? Do the sideboard cards support that plan? For the decks in question, how much better is a Red Elemental Blast (which demands mana be kept up for it until it can be used) than a card that actively reduces the opponent’s life total?


Building a sideboard will seldom be an exact science, as the decks you are going to play every round will never be a known quantity. But there are habits that you can get into that will help you consistently have a stronger sideboard—and thus deck—but you can’t expect it to learn it all here. You’re going to need to get out there and see what works (and sadly, what doesn’t work, as well) for yourself. Keeping these tips in mind should go a long way toward helping you help new player or perhaps even give you some insight into your own sideboard plans.

~ Christopher Walton in the real world

im00pi at gmail dot com

Master Shake on The Source

@EmperorTopDeck on Twitter