Commander Glossary
Rule 0 is the conversation a Commander table has before the game starts, to agree on what kind of game it's going to be. It isn't an official rule — it's community shorthand for the social contract, and it works entirely by consent: if one player isn't comfortable with a proposal, the default is the official rules. Done well it takes about ninety seconds and prevents most bad Commander nights.
It's the agreement about what game you're playing, made before you start playing it. The name comes from the idea that it sits before rule one.
Rule 0 appears nowhere in the Comprehensive Rules and nowhere in the official Commander rules. It's a community term for a community practice, and it covers two related things that are worth separating. The first is expectation-setting: how strong is everyone's deck, how does it want to win, roughly how long will this take. The second is rules variance: proxies, a house ban list, an unusual commander, a card the group has agreed to allow or disallow.
The first kind happens at nearly every Commander table, often without anyone naming it. The second kind is rarer and needs more care, because it's asking people to play something other than the game they signed up for.
The load-bearing part of the whole practice is the consent rule, and it's simple:
If even one player isn't comfortable with a Rule 0 proposal, the answer is no and you play by the official rules. Not a majority vote — one objection is enough.
— the norm the whole thing rests on
That's what makes Rule 0 a conversation rather than a loophole. There's no rule backing it up, so it has no force beyond agreement — which means the only way it can be misused is by pressuring someone into agreeing. More on that below.
Rule 0 means you can play whatever you want as long as you mention it first.
Announcing something isn't the same as getting agreement to it. "Rule 0, I'm running a banned card" is a request that any player can decline, and saying it out loud doesn't convert it into permission. The mention is the start of the conversation, not the end of it.
Six questions, none of which require anyone to reveal a decklist. In a pod that knows each other, the first two take about twenty seconds.
What bracket are we playing?
The single most useful question, and the one that got much easier to answer once brackets existed. One number, understood roughly the same way by everyone, instead of an invented 1-10 scale.
Roughly how does your deck win?
Not a decklist reveal — a category. Attacking with creatures, assembling a two-card combo, grinding value until nobody can keep up. Knowing the shape tells everyone how the game is likely to end.
What turn does your deck want to win on?
The most honest proxy for power level there is, and much harder to fudge than a bracket number. A deck aiming at turn six and a deck aiming at turn twelve should not be at the same table.
Is there anything you'd rather not play against?
The question that actually prevents bad nights. Mass land destruction, stax, infinite combos, extra-turn chains, heavy discard — people have strong feelings, and it costs nothing to ask first.
Any proxies, house rules, or unusual cards?
Better raised now than discovered mid-game. This is also where genuine rules variances belong — playtest cards, a custom commander, an unofficial ban list your group uses.
How long do we have?
Rarely asked and quietly the most practical. A pod with ninety minutes left should not start a game between two decks that both want to go long.
The third one — what turn does your deck want to win — deserves singling out. Bracket numbers can be sincerely misjudged, because people rate their own decks generously and inconsistently. "About what turn do you win?" is much harder to get wrong, and two players whose answers are six and twelve have learned something important about each other in four words.
"Bracket three for me, creature combat, probably wins around turn ten if nobody stops me."
"Also three, but I'm a combo deck — two-card combo, and it can come together turn seven or eight."
"Two, honestly. It's a precon with maybe ten cards swapped."
Now the table can adjust before anything is at stake: the precon player might swap decks, or the other two might agree to play more cautiously and leave them alone early. The point isn't to make everyone identical — it's that nobody is surprised.
For most of Commander's history, Rule 0 had no shared vocabulary. Players used a made-up 1-10 scale where a "seven" meant something different at every table, so the conversation happened but frequently failed — everyone answered honestly and still ended up mismatched.
Wizards' official bracket system fixed the vocabulary problem. Five numbered brackets with published definitions mean an answer of "three" carries roughly the same information everywhere, which makes Rule 0 shorter and much more accurate. If you only learn one thing before your next pod, learn the brackets — see The Commander Bracket System, Explained → and What Is EDH Power Level? → for how they relate to the older informal scales.
What brackets don't do is make the rest of the conversation unnecessary. A bracket tells you roughly how strong a deck is. It doesn't tell you whether anyone at the table will be miserable if you blow up all the lands, whether the group allows proxies, or how much time you've got. Those still need asking.
Aim the objection at the game, not the person, and raise it before the first turn rather than during turn eight.
Most people find this the hard part, and the fix is mostly having a phrasing ready. Compare "that deck sounds unfun" with "that sounds like a higher-powered game than the deck I brought — can I swap, or should we shuffle the pods?" The second version declines the match-up and leaves everyone's deck alone, which is both kinder and more likely to work.
Three things worth internalising. Declining is the mechanism working. Rule 0 exists so people can opt out before there's anything at stake; a conversation where nobody could ever say no isn't a conversation. You don't owe a justification. "I'd rather not play against mass land destruction" is a complete answer and doesn't require a defence of why. Timing is most of it. The same objection raised in the pre-game is a scheduling detail; raised on turn eight, when someone is about to win with the thing you didn't mention, it's an argument.
And if you're on the receiving end: take the no. Someone declining your combo deck isn't a verdict on your deckbuilding, and pushing — "come on, it hardly ever assembles" — is exactly the pressure that makes people stop being honest in Rule 0 conversations at all.
A recurring playgroup usually accumulates a handful of agreed variances. The problem is almost never agreeing on them — it's remembering them three weeks later, when half the table recalls the rule differently and the other half wasn't there. Write them down somewhere the group can see, and the same argument stops recurring.
Common ones worth considering, in rough order of how often groups adopt them: no mass land destruction; take-backs allowed until you've tapped mana or passed priority; a soft turn timer once games run long; spectators don't advise on plays; and a short list of specific cards the group would rather not see. Note that the free first mulligan is not a house rule — it's already part of official multiplayer Commander, and plenty of groups adopt it as though it were optional. See How Mulligans Work →.
One caution about unbanning cards. It's the most common Rule 0 variance and the one most likely to go wrong, because banned cards are usually banned for warping games rather than for being merely strong. If your group wants to try one, try it for a night and talk about it afterwards rather than adopting it permanently up front — and read The Commander Banned List, Explained → for why the card was banned before deciding the ban doesn't apply to you.
Treating an announcement as consent. Saying what you're doing is not the same as the table agreeing to it. If someone says no, the answer is no.
Sandbagging the bracket. Describing a deck as weaker than it is buys you one good game and costs you a playgroup's trust. The people you're playing with will notice by turn seven.
Having the conversation after the game starts. Rule 0 is a pre-game practice. Raising it mid-game reads as trying to change the rules once you can see who's winning.
Ambushing a new player. Someone who has played four games of Commander cannot meaningfully answer "what bracket is your deck?" Ask what they're playing and look at it with them instead of asking them to self-assess.
Treating the agreement as a promise about the outcome. A table agreeing to a bracket-three game hasn't guaranteed a close one. Variance still exists, and someone winning quickly isn't automatically a Rule 0 violation.
Rule 0 is the informal, unofficial convention that a Commander table agrees on what kind of game it's playing before the game starts. The name comes from the idea that it sits before rule one: you settle what game you're playing, then you play by the rules. In practice it covers both power-level expectations and any house rules or variances the group wants to use.
No. It appears nowhere in the Comprehensive Rules or the official Commander rules — it's community shorthand for a social practice. That's precisely why it works by consent rather than by force: there's no rule to appeal to, only an agreement to reach.
Only if everyone genuinely agrees, and 'genuinely' is doing real work in that sentence. A table can agree to unban a card for a game, but Rule 0 is a request, not a permission slip. If a single player is uncomfortable, the default is the official rules — and pressuring someone into agreeing is the most common way Rule 0 gets misused.
Brackets are the vocabulary; Rule 0 is the conversation. The bracket system gives you a shared 1-5 scale that means roughly the same thing at every table, which makes the Rule 0 discussion far shorter and more accurate than it used to be. Brackets didn't replace Rule 0 — they gave it a common language, and there are still things brackets don't cover, like whether anyone minds mass land destruction.
Say so plainly and early, and aim it at the game rather than the person: something like "that sounds like a higher-powered game than the deck I brought — can I swap to something else, or should we find a different match-up?" A table that can't absorb that answer is telling you something useful. Declining is the mechanism working, not a failure of it.
TurnZero keeps a record of your pod's nights and the decks that showed up, so next week's Rule 0 conversation starts from what actually happened.
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