Gavin’s Format of the Month – August 2020: Sideboards

From the inception of the Commander rules website until about 2011, there was a section for “optional rules” which the RC felt were interesting to some, but didn’t have enough common appeal. One rule which I was always a fond of was the use of sideboards for more high-powered games.

There wasn’t much in the vein of cEDH back then; a few groups in Ottawa and Paris played cutthroat games; but there were plenty people at the next tier down and I always felt that the use of sideboards (even in one-game “matches”) made those games much more interesting. If the other players all agree (in advance), playing with sideboards is viable variation of the core rules.

There’s nothing wrong with a Fencing match, but there’s no room for a broadsword.

To explain why, we need to dig into the RC’s stance on “answers” in Commander decks. Specifically, what do we consider reasonable expectations on a deck builder?

Should you play “answers” in your deck?

Yes. Obviously.

Interactivity is fundamental to any interesting Commander game. Even if your deck’s plan is an all-out blitz, you’re still looking to thwart your opponents’ plans by taking away their time. Most of the time, interactivity comes from cards which answer or preempt an opponent’s threats… removal, hand disruption, counterspells are obvious. Bigger creatures block attackers, flying creatures obviate a control deck’s blockers. The cycle goes on, but it is the interactions between our cards and our opponent’s game state which make Magic interesting.

That’s to to say that answers have to be singular in focus. Much of the interactivity in EDH games comes from cards which answer a threat and leave some resource behind: Stomping Indrik or Flame-tongue Kavu or Contagion Engine. That’s because longer games are more likely to resolve through attrition, and answers which trade 1-for-1 are inherently dangerous in a multiplayer environment. The term “Coup fourré” refers to an answer which immediately presents a threat… arguably the best kind of answer.

The downside to flexible answers is that they’re costed appropriately… the aforementioned “killer Kavu” is 4 mana, where Flame Slash costs 1. Creature-based answers are always sorcery speed… and as decks get more faster, the window to answer threats gets smaller. Draining Whelk is great in a 10-turn slugfest, and unplayable if someone is going to combo off by turn 6-8.

In higher powered, faster, games your answers must be more (mana) efficient… but those answers do nothing else.

In higher powered games, answers must be more (mana) efficient but efficient answers usually don’t advance your plan. They don’t enrich the ensuing game state as much as an expensive answer would (albeit, they enrich the ensuing game state more than an ineffective answer which doesn’t stop the game from ending). They’re a necessary evil sometimes; moreso as the power level rises.

How many [good] answers is enough?

The second problem with “answer” cards is that you have to draw them in time… “There are no wrong threats” and all that. With a 100 card singleton deck, the frequency with which you[1] draw any particular answer is low, which means that you need to put several in your deck to reliably have one when a threat arises. (I’m discounting the efficacy of answers against specific threats, and starting with the simple model of “every answer completely negates a particular threat”… later we’ll talk about different types of answers for different types of threats).

Counterplay is the idea that you can increase your chances to win by foiling an opponents’ plans, as well as advancing your own, and the interesting decisions which arise from balancing the two.

Unfortunately, putting too many answers in a deck is usually a bad thing, from both strategic and entertainment perspectives. Too many efficient answers and you’re not DOING anything to advance your position… too many expensive answers and you’re probably not doing anything at all.

So, how many answers fit in that goldilocks zone? It depends on how likely the threat is to occur. If you’re going to face a particular danger multiple times every game (say, a big creatures) then you want to have answers consistently… 10-20 creatures of your own, or targeted removal, etc. “Wide” creature strategies are also pretty common, so board wipes are popular… but you don’t need to have them nearly so often. 5-10 ways to deter a creature swarm: a mix of resilient blockers, sweepers, or a good crackback threat can be enough.

There are other types of cards which can threaten to take over the game along other “axes”… graveyard recursion, enchantments (From Omnipotence to Vicious Shadows), Artifacts, strategies which don’t win by attacking, etc. Perhaps the most prevalent is Land Ramp[2]… but that’s a topic for another day.

These “off-axis” threats require more specific answers… counterspells to stop infinite mana, disenchants to get rid of non-creature stax pieces. Stopping reanimator requires Bojuka Bog or Faerie Macabre, and indestructible or hexproof creatures can’t be answered by every removal spell.

Fortunately, those threats are less common… so in most Commander games we can:

  1. Hope they don’t show up at all.
  2. Assume they show up late enough that we can play less efficient answers which also serve to advance our board state.
  3. Play a small number of efficient answers and hope that other players do the same, such that at least one person has an answer to an early problem.

#1 is sometimes viable, but you shouldn’t be salty when you let an opponent go unchecked (and most of us don’t like flipping coins so you’ll need to find other opportunities for skill play if counterplay isn’t your thing).

But what happens when resilient or niche threats show up regularly and repeatedly in the early game? That’s what we’re talking about when we say “high powered environment.”

What happens when we play enough answers for every type of threat?

The risk (as the RC sees it) with cut-throat EDH is that, to be reliably interactive in an environment with regular, early-game, game-ending threats a deck needs to contain a very large “critical mass” of narrow and efficient answers. To make sure you’ve got lands and at least one of the “right answers” before turn 3-4, a deck needs to play 40+ narrow answers, leaving very little room for cards which advance the game and do proactive, opportunity-for-interaction things. Instead, these decks play a small set of highly reliable, hard-to-interact with threats which take up fewer slots.

The risk with cut-throat EDH is that, to be interactive in an environment with regular, early, game-ending threats a deck needs to contain a “critical mass” of narrow answers.

Moreover, because of the math of drawing a small hand from a large deck, the number of answers that must be in the deck to reliably draw at least one means that you’ll usually draw more than one.

The result is games are a tight-knit “fencing” match of counterplay, seeing who can thread the needle of opposing answers to land a threat. This contrasts with the “broadsword” or “claymore” style of swordplay that most people look for in Commander game. There’s nothing intrinsically wrong with a “fencing matches”… they’re elegant and skill testing in the extreme. Leaning on the metaphor a bit, they’re harder for the audience to understand though and there isn’t as much room for creative expression as there is in a high-variance format[3].

The RC generally feels that creatures are central enough to Commander that players can be expected to play a reasonable number of answers to “normal” creatures… but must-answer enchantments and artifacts, indestructible creatures, and graveyard strategies are less frequent. Expecting players to pack 5-10 answers to every threat type is undesirable.

How should sideboards work? Do they help?

Hopefully, it’s obvious by this point why sideboards could make the game more interesting. By allowing game-time flexibility in deck composition, high-powered players can cut irrelevant answers and play more proactive cards[4]. The questions which arise are:

1) What’s the downside?

Regular readers[5] know that I believe every variant has a downside to go with its upside, and sideboards are no exception. The most important one is sideboards let people play cards with large caveats while often avoiding them. As long as everyone has the same opportunity that’s (probably) ok… but sideboards only work if everyone has a sideboard.

Another downside to sideboarding is that the narrow “silver bullets” which become playable are often feel-bad cards. Chill, Choke, and even Leyline of the Void can be groan-inducing when they land well… and that’s why Sideboards aren’t part of the core Commander rules. The RC doesn’t think that they enhance most playgroup’s fun quotient.

2) How would sideboards work in single-game matches?

TL;DR – sideboard after revealing all commanders.

To make a sideboard useful (see question 4), you need to know something about your opponent’s deck. I messed with the idea of allowing mid-game sideboards, but the games which need more answer specificity need it sooner not later. Fortunately, the pregame procedure for Commander has a perfect opportunity… an opponent’s commander tells us a lot about their deck (especially in focused metagames with Tiered commanders). If we know someone is playing a graveyard deck, pulling in even 2-3 silver bullets substantially decreases the chances anyone goes off with Hermit Druid on turn

3) How big should sideboards be in Commander?

Back in the days where sideboards were listed on the website, sideboards were 10 cards… I don’t actually remember where that number came from. For simplicity’s and consistency’s sake though, 15 cards is the right number. If you’re playing a game where silver bullets are allowed and needed, that gives you 3-5 cards in each of 3-5 categories, which (assuming you have 3 opponents and a few maindeck answers each) increases the chances of someone having an answer in the opening turns to a reasonable 80%+ range.

Unlike other formats , you still have to sideboard out one card for each card you bring in. Commander has a maximum deck size as well as a minimum.

4) If I’ve got a sideboard, do wishes work?

Wishes (cards which bring other cards into the game from outside) are an interesting piece of templating technology which first arose in Odyssey block… and with the rising popularity of 1-game matches for Standard (thank to Arena) they’re seeing a surge of popularity in newer sets. Unfortunately, they come with all the same caveats that sideboards do… they drastically lower the cost for feel-bad silver bullets. That’s part of why the RC doesn’t want to see wishes in Commander, and it raises the question of whether Wishboards should be a thing in games with sideboards.

Given the time restrictions on competitive games, my inclination is that wishes are probably too slow… but I’ve leery of how burning wish was so powerful in Vintage, usually fetching Yawgmoth’s Will to end the game. Wishes, like Tutors, get around the singleton nature of Commander… and tutors factor quite heavily into cEDH games. Wishes are generally more expensive than the (best) tutors. I would probably not allow opponents to play with wishes even if we were sideboarding, but YMMV and I’m really not knowledgeable enough to decide without more testing.

5) Can we use sideboards for casual/mid-power games?

[Keeping in mind that this is still a variant, and requires permission from every opponent before it applies]

Contrary to everything I’ve said above, yes you can… but everyone (starting with you) needs to obey the same kind of social contract which makes Commander work in the first place. Use your sideboard to make the game more interesting for everyone… and that means starting with a conversation about what they find intersting. Include answers which slow your opponents down, but don’t shut them out.

Better yet, bring in answers which capitalize on opponent’s predictability, and use them to do interesting things. If you tell them you’re doing so, it will have the collateral benefit of encouraging them to be less predictable!


[1] Granted, one of the advantages of a multiplayer is that you can be saved by other players in a sort of diplomacy/prisoner’s dilemma way. Unfortunately, it’s a tragedy of the uncommons… the person who spends a resource to stop a threat rarely comes out ahead of the other opponents who didn’t. (Again, that’s why Draining Whelk and the like are popular, because answers which put you ahead avoid this trap). Worse, the multiplayer nature can also become a race to the bottom… relying on other players to break up combos or Path to Exile an early monster means you can put more threats in your own deck.

[2] Unfortunately, there really aren’t a lot of good answers to land ramp, short of Armageddon effects which reset everyone back to square zero and make the ensuing game much less interactive. There are a few, but it’s one of the things we hope to see more of from future magic sets.

[3] As it turns out, real broadsword fighting between experts actually involves a lot of counterplay and is extremely skill-testing. The difference is that broadsword matches between casual competitors is at least interesting… fencing between amateurs is boring for everyone.

[4] They can also play more relevant answers… again, there’s nothing wrong with playing control decks if that’s what everyone wants. But at least there’s more room to think.

[5] I’m not convinced such a thing exists, but grant me the rhetorical device :).