THE RULES

YOU ALREADY OWN A DECK

Take a Commander deck off your shelf. Keep the commander. Cut the 99 down to 39.

That's a Captain deck.

Same singleton rule. Same color identity. Same legendary creature in charge. Nothing to buy, nothing new to learn, and about twenty minutes to convert a deck you've already built.

THE BASICS

Forty cards, including your Captain. Twenty life. One versus one.

YOUR CAPTAIN

Any legendary creature. There are 3,472 legal Captains, and 2,190 of them cost a dollar or less.

Your Captain starts in the Captain's Seat. Cast it from there any time you could normally cast it.

The seat tax: each time your Captain returns to the Seat, it costs {2} more than the last time you cast it.

Whenever your Captain would go to any zone other than the battlefield or the Seat, you may put it in the Seat instead. Dies, exiled, bounced, milled, tucked: same rule, every time.

There is no Captain damage. Twenty life is the only clock that matters.

BUILDING

Singleton. One copy of each card, except basic lands.

Color identity. Every card must fit your Captain's, exactly as in Commander.

That's the whole deckbuilding rule at the casual level. 32,476 cards are legal.

PLAYING

No mulligans. Ever. Keep what you draw.

Forty cards with about seventeen lands makes hands naturally keepable. And because nobody ever mulligans, nobody ever knows whether their opponent kept a good hand. Hand quality is hidden information for the first time in Magic. Read your opponent, or don't.

Whoever plays first skips their first draw.

Everything else is normal Magic.

THE TWO TIERS

CASUAL

Casual has no deck rules at all.

Mash precons together. The first legend you pull is your Captain. Proxy whatever. Bring your worst. The only rules are the game's rules. Nothing is illegal in Casual, so there's nothing to check and nothing to argue about.

COMP

The real format. Four rules.

1. Register fifty. Your forty plus a ten-card sideboard, exactly fifty. The whole fifty is judged as one pool, so nothing hides in the board.

2. Three Game Changers, maximum, across those fifty. The full list is at playcaptain.gg/lists. It covers fast mana, mass land denial, free interaction, and the tutors. Because the tutors are on the list, there is no separate tutor rule to remember.

3. Best of three, with the sideboard.

4. Paper only, and no Reserved List. If cardboard can't summon it, it isn't in the format. And if Wizards can never print it again, it isn't in Comp either. That's an availability rule rather than a power rule, and it's the reason a tuned Comp deck costs $37.53 instead of the price of one dual land.

Your Captain is locked at registration. It stays in the Seat all match. Because your color identity can never change, any legal fifty stays legal in every game. Checked once, never again.

SIDEBOARDING

Between games, swap any number of cards between your forty and your ten. However many, however often. Your opponent never has to police it.

Ten of forty is exactly the same 25% that fifteen of sixty gives constructed Magic. But every one of your ten is a singleton, so ten board cards means ten different answers instead of three copies of one. Three distinct hate cards give you a 64% chance to see one by turn five, and four gives you 75%. That is eleven cards seen: your opening seven plus four draws, because you skip your first draw on the play. Enough to fight anything. Never enough to lock it out.

And here's the decision no other format asks you to make. With no mulligans, your land count is a live dial:

Two sideboard lands move your screw rate from 9.4% to 5.3%. Three takes it to 3.9%, and your flood rate climbs to meet it. Against a deck that punishes stumbles, buy consistency. Against a grind, spend it elsewhere.

Those are cards you're not spending on hate. That's the trade, and you make it after game one, with information you just earned.

NOTHING IS BANNED FOR POWER

No card is excluded from Comp for being too strong. Two kinds of cards are excluded, and neither reason is power: cards that cannot function in a registered 1v1 match, and cards you cannot reasonably buy. Both lists are published at playcaptain.gg/lists.

Some cards are watched. The current list is published and dated, and it lives with the Game Changers at playcaptain.gg/lists, so these rules never go stale.

If the data says a card warps the format, it moves to Casual. Cards get a price, not a prohibition.

THE TWO LISTS

They do different jobs. Casual Only cards are not legal in Comp at all. Game Changers are fully legal, but you may only run three.

Both lists are published and dated at playcaptain.gg/lists, so a revision to either one never makes this page stale.

THE NUMBERS

About one opener in nine is rough. No mulligans means you play it. But the same player getting a rough hand in two of three games happens 3.5% of the time, and it happens to one player or the other 7.0% of the time. Variance is a story you tell, not a match you lose.

Games end on turn seven to nine. Aggro goldfishes a kill on turn five. A tuned combo deck comes online turn seven or eight. Both clocks land in the same window, which is why it's a race.

Combo is a deck, not the deck. Singleton kills redundancy, twenty life keeps a clock pointed at you, and best-of-three lets the field answer back.

A tuned deck costs $37.53. That is THE COVER CHARGE, a Rakdos aggro fifty under Judith, the Scourge Diva, priced card by card and checked by the law engine rather than estimated. The median legal card is 23 cents, and 93% of the format costs five dollars or less.