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Sideboards in MTG: All You Need to Know!

Sideboards in MTG can take your deckbuilding to the next level! Here we explain what sideboards are, how they work in paper and in MTG Arena, and how to build your own.

If sideboard cards aren’t in your starting decklist, how useful can they be in a game? Find out as we dive into Sideboards in Magic: The Gathering!

a 60 card mtg deck with a 15 card mtg sideboard

What is a Sideboard in MTG?

A sideboard is an additional set of cards (usually 15) to accompany your main deck. The sideboard exists outside of the game you’re playing, but between games, cards in your sideboard can replace cards in your main deck to modify your deck against your opponent.

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How do You Use a Sideboard?

MTG matches can often be played in a best-of-three setting or a best-of-five setting, especially during tournaments. For the first game of the match, the sideboard (usually) doesn’t do anything, since you have to start with your main deck.

In between each game, there is a “sideboarding phase”, where you can swap cards between your main deck and sideboard. Yeah, it’s as simple as that. In the same way that you would tweak your deck over time to make it play better, you can tweak your deck in the middle of a match!

How Does a Sideboard Work in MTG Arena?

MTG Arena’s sideboard works a bit differently than in paper. If you’re playing best-of-three games online, traditional sideboard rules apply. However, things get a bit interesting when you play best-of-one matches.

In best-of-one, your sideboard size gets reduced to seven cards. But, since you’re only playing one game per match, there is no sideboarding phase. You might think sideboards in best-of-one matches are useless, but this isn’t necessarily true.

Some cards use the sideboard in the middle of a game. Let’s take a look at Mastermind’s Acquisition to get a better idea of what I mean.

Mastermind's Acquisition mtg card

Mastermind’s Acquisition lets you grab a card from outside the game and put it in your hand. You might think this means any card in your entire collection of MTG cards, but that isn’t the case.

When a card says “outside the game,” it usually means your sideboard.

To make the game fairer to players who don’t use such cards, MTG Arena restricts players to seven cards in their sideboard when playing best-of-one matches.

Do I Need a Sideboard in MTG?

You can absolutely choose not to have a sideboard in MTG. I obviously recommend having one whenever you can, since there’s no downside to having one. Even if you don’t have the perfect cards for your sideboard, that’s okay. At the very least, bring 15 random (or semi-random) cards to your next match. You never know whether they’ll come in handy.

How to Build a Sideboard

I’ve already written a guide on how to build an MTG deck, which alone can be a daunting task. You might think that since sideboards are smaller than main decks, they must be easier to build. This couldn’t be further from the truth. I find sideboards to be the trickiest part of building an MTG deck, and sideboards are never perfect.

Here’s how I would go about this process.

Identify Your Deck’s Strengths and Weaknesses

As you start to play a lot of games with your deck, you’ll notice that it will struggle against certain strategies and excel versus others. This is to be expected, and overall, I think it’s a good thing, since it keeps Magic as a whole an interesting game.

Just because you struggled with your first game, however, doesn’t mean games two and three have to go the same way.

Let’s say you’re playing a blue-white deck, and your opponent’s playing a burn deck with lots of Lightning Bolts and Lightning Helixes. You probably struggled during your first game because they played a bunch of burn spells and reduced your life total to zero before you could even get started. This is where you’ll want lifegain cards like Sunset Revelry and Timely Reinforcements at your disposal. These can replace your slower cards that won’t be of much help.

Pack Some Silver Bullets

In Magic, silver bullets are cards that basically win the game on the spot. Silver bullets tend to work exceptionally well against a few strategies but are generally useless against others. Rest in Peace is probably one of the most famous silver bullets in Magic. It completely shuts down graveyard strategies, but it doesn’t do a whole lot else. This card can either be game-winning, or completely useless. Definitely a sideboard card.

Aether Gust, Mystical Dispute, and other similar cards can fall under this category too. They only work against cards of a specific color and are otherwise useless or below-average cards. Again, great sideboard cards, but I wouldn’t put them in my starting deck.

Sideboard cards are only useful if you, well, use them. Pay attention to what decks other people are playing and adjust accordingly. You may be running four copies of Mystical Dispute in your sideboard, but if nobody in your local tournament scene plays blue decks, what’s the point? Ideally, your sideboard prepares you for whichever decks are most popular at the moment. This means your sideboard is going to evolve quite a bit over time.

Don’t Stray too Far from Your Strategy

Remember, your goal is still to win! If you sideboard out your win conditions and other key cards, then your deck will become worse, not better. The ideal sideboard helps you counter your opponent’s strategy without losing focus on your own.

Compare the following two cards:

Which one is better? The answer is: it depends. While Rest in Peace does a better job of completely shutting down graveyard strategies, Sanctifier en-Vec can attack your opponents. If I were playing a control deck, I’d prefer Rest in Peace, since I wouldn’t want my opponent playing any cards from their graveyard. If I were playing an aggro deck, I’d prefer Sanctifier en-Vec, since I can also attack my opponent with it.

Make Sure Your Numbers Add Up

Remember, when you add a card from your sideboard, another card leaves your main deck. If you plan to swap in five cards against a control deck, make sure you have five cards that you no longer need in your post-sideboard games. If every card in your main deck already performs well against a control deck, those 15 sideboard slots will be best used against other decks.

Sideboard Example: Burn

MTG burn deck with example sideboard

Here’s my burn deck. Its plan is to play as many damage spells as possible to reduce the opponent’s life to zero. Let’s go over each and every sideboard card to understand what makes those 15 cards so special.

  • Lurrus of the Dream-Den: Lurrus is this deck’s companion. Companions can enter the game directly from the sideboard, so it’ll never enter the main deck. It’s just a useful card to have available at all times during a game.
  • Deflecting Palm (x3): For a burn deck, Deflecting Palm is better than a typical damage prevention effect because it also redirects damage to the opponent. This makes it a damage spell and a damage prevention effect all in one, a perfect card for a burn sideboard!
  • Sanctifier en-Vec (x3):  Great sideboard cards are also versatile. Not only does Sanctifier en-Vec perform well against red and black decks, but it keeps graveyard strategies in check too. Since it’s a creature, it’ll help deal some damage during a game.
  • Path to Exile (x2): This is probably my least favorite card in the sideboard, which is why there are only two of them. While Path to Exile does an excellent job at dealing with creatures for only one mana, it doesn’t advance the burn deck’s gameplan. Sometimes, though, you’ll find that playing a removal spell instead of a burn spell is worth it.
  • Roiling Vortex (x3): Roiling Vortex is what I like to call an anti-sideboard card. Remember that you’re not the only one with a sideboard – your opponent has one too! If you suspect that your opponent will sideboard in some lifegain effects (which are really good against burn), consider bringing in this enchantment to shut those cards down. Anti-sideboard cards are great insurance against your opponent’s sideboard.

(Plus, Roiling Vortex deals damage, which advances your game plan. Awesome!)

  • Smash to Smithereens (x3): This is obviously for artifact decks. Similar to Deflecting Palm, Smash to Smithereens is better than a typical artifact destruction card because it also deals damage. Another perfect sideboard card for burn.

What I love about this sideboard is that the deck remains focused on its game plan even after the sideboard cards come in. Each card has a specific reason for being there, meaning none of the 15 sideboard slots are wasted.

Can You Look at Your Sideboard During a Game?

You are not allowed to look at your sideboard during a game. You are only allowed to view your sideboard in between games, or when a card makes you search your sideboard, such as Cunning Wish.

Sideboards in Limited

In Limited formats, such as Draft and Sealed, you build your deck as you go. This is usually done by opening booster packs and building a 40-card deck from whichever cards you open. Since you’ll have more cards than you can put in your deck, you’ll have a handful of cards left over. Those leftover cards are your sideboard in Limited.

Sideboards in Commander and Brawl

There is no sideboard in Commander and Brawl. These formats are usually played in best-of-one matches anyways, so there wouldn’t be much use for a sideboard.

A note about Sideboards in MTG

So, there you have it. Now you know how a sideboard works in MTG, how to build one, and how they vary across formats.

Even if you aren’t planning on attending any ultra-competitive tournaments anytime soon, I’d still recommend building a sideboard to accompany your deck. It’s fun, and it gives you a deeper appreciation for MTG deckbuilding as a whole.

For more deckbuilding tips, see: How to Build an MTG Deck and How to Build a Commander Deck in MTG and to choose the type of deck you’d like to build, see Deck Types and Popular Deck Archetypes!

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Hi, I’m Emily, the tabletop gamer behind My Kind of Meeple. If this article helped you, I’d be honoured if you’d say, “Thanks!” with a £3 coffee on Ko-fi.

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