Decks

Legality

Each format's rules (deck size, copies, banned and restricted cards, color identity, commander pairings read from the cards' own text) with legality from Scryfall, read October 22, 2026. The numbers (deck size, sideboard, copies, life, commander damage, points cap) come from the formats registry the Formats pages read (cards/formats.json, each rule with its source and the day it was checked); until that file loads, or if it can't, the same numbers built into the page are used, and the page says so. Every deck shows its format's rules in a panel with who keeps them (linked), the day they were checked and the next list update (marked estimated when it was worked out from a schedule, not announced), and links the format's own page.

Every format

28 formats, grouped by family in the picker: Constructed (Standard, Pioneer, Modern, Legacy, Vintage, Pauper, Penny Dreadful), Commander and its cousins (Commander, Duel Commander, Pauper Commander, PreDH, Oathbreaker, Tiny Leaders, Brawl, Standard Brawl, Competitive Brawl), Highlander (Canadian, 7 Point, Big Apple), Retro (Premodern, Old School 93/94), MTG Arena (Historic, Timeless, Alchemy, Gladiator), Limited, and Captain and casual. What sets the newer ones apart:

• Pauper Commander: 100 cards, 30 life, 16 commander damage. The commander comes from Scryfall's is:paupercommander list (a creature, Vehicle or Spacecraft printed at uncommon, or an uncommon Background beside a commander that says "Choose a Background"; two commanders as Commander allows); the 99 from Scryfall's paupercommander legality, which covers the 99 only since November 26, 2024. PDH's own banned list, not Pauper's. Where Scryfall and PDH's written rule part (The Zeta Set's 12 commons, legal in the 99 on Scryfall though their only common printing is a Secret Lair one), the deck says both and follows Scryfall.
• Canadian Highlander: at least 100 cards, one of each but basic lands and cards that say otherwise, Vintage's banned list (a card on it reads as Vintage's ban, with Vintage's date), no sideboard (so a companion ability does nothing, and a sideboard card is flagged), wishes don't function (said, card by card), and at most 10 points from the council's list; the deck shows its points against the cap with the list's date.
• 7 Point Highlander: at least 60 cards and a 15-card sideboard, singleton, Vintage's banned list, 7 points, or 8 when the deck and sideboard hold no Reserved List card (Scryfall's reserved flag). Lurrus of the Dream-Den and Lutri, the Spellchaser cost their points only when marked as the companion.
• Big Apple Highlander: Premodern's card pool with Premodern's banned cards legal, less the format's own six ante cards, singleton, 60 and 15.
• Gladiator: at least 100 cards, singleton, no sideboard, no commander, its council's banned list (Scryfall's gladiator legality).
• Penny Dreadful: Scryfall's penny legality, 60 and 15, four copies. Where this site's check finds Scryfall and the official list part, both are said with the list's date.
• Old School 93/94: Scryfall decides it printing by printing; a card reads legal when any of its printings is, and the rules panel says to check the printing you own. Its 22 restricted cards are one copy each.
• PreDH: cards first printed by New Phyrexia (May 13, 2011), Commander's rules and banned list, 40 life.
• Tiny Leaders: 50 cards counting the commander, every face mana value 3 or less (Scryfall's tlr legality), a 10-card sideboard that is part of the deck (inside the commander's colors, one copy across both), cards banned as the commander only, and Lutri, the Spellchaser banned as a companion only (said when it sits in the sideboard).
• Commander sideboards: Commander games don't use sideboards (Comprehensive Rules 903.5e, September 25, 2026), so a card left in a Commander-family deck's sideboard is flagged as not part of the deck; Duel Commander's companion may sit outside the deck as a 101st card (Duel Commander rules 206.3). A card banned as a companion only (Lutri, the Spellchaser in Commander, Duel Commander and Tiny Leaders) is something to fix when marked as the companion.
• Where it's played: a deck in a format played only on MTG Arena (Brawl, Competitive Brawl, Gladiator, Alchemy, Historic, Timeless) or only on Magic Online (Penny Dreadful) counts as played there until you choose otherwise, so an Arena deck shows its Wildcards action.
• Competitive Brawl: Brawl's 100 and its card pool, 25 life, no free mulligan, its own list of cards banned as the commander.
• Alchemy: 60 and 15 on MTG Arena; the deck says the format leaves MTG Arena on February 2, 2027.
• Banned as commander: in Duel Commander, Competitive Brawl and Tiny Leaders, Scryfall's "restricted" means banned as the commander only, so such a card is flagged in the command zone and legal in the deck.
• Oathbreaker: two planeswalkers with Partner may lead, each with its own signature spell inside its own colors (906.3b, 906.4b); a signature spell never widens the deck's colors.

Where this site's check of the official list finds a card it bans while Scryfall reads it legal (Alchemy's Cori-Steel Cutter and Leyline of Resonance today), the deck says so beside the result and checks by the card data. A legality Wizards or a committee announced for a day still ahead reads that day ("Joins Commander on November 13, 2026"), never only "not legal".

• PDH Home Base rules (Pauper Commander)
• Canadian Highlander points list and its primer
• 7 Point Highlander rules and points list
• Big Apple Highlander (mtgnyc.com)
• Gladiator
• Penny Dreadful
• Old School 93/94, Eternal Central rules
• PreDH (Star City Games, March 2, 2023)
• Tiny Leaders: Reborn rules and banned list
• Introducing Competitive Brawl (Wizards)
• Duel Commander banned list
• Oathbreaker rules (906.3b, 906.4b, 906.13)
• State of the Formats 2026 (Alchemy leaves MTG Arena on February 2, 2027)

Points

A Highlander deck counts the points of every card in the main deck and sideboard (the maybeboard aside) against its cap:

points = sum over pointed cards of points x copies

Over the cap is something to fix, said with the number to take out. The header shows the total, each pointed card shows its points in the list view, and the Points panel names them with the list's date and source. A playgroup list can carry its own points (one card per line, the number before or after the name) and a cap; a deck that follows it counts those instead of its format's, so a local or Scandinavian list works without the site publishing it. Its link carries the points too; a link made before playgroup lists had points never removes a list's points, and a newer link that would take them off says so before you update. A deck that follows a playgroup list with points reads "Legal under" that list, with the format's own count beside it; its share link carries the list's name, cap and the points of the cards it holds, so the shared page counts the same way and says so. A copy saved from a shared link ("Save to my decks" on the shared page, or "save a copy" in Decks) follows the list it was built under: a saved list of the same name, or a new one made from what the link carries, and says which. The shared page also checks the banned cards that rode in the link, and leads with the points when the deck is over the cap. Adding a pointed card says the new total.

Rulebreaker commanders

Mystery Booster Commander Edition (released October 19, 2026) brings the rulebreaker ability word: a line that changes how a deck is built while that card is the deck's commander. Decks reads each rule from the card's own text, so a later card with the same wording works too:

• Seluma, Light of Aysen: Angel cards of any color identity, and any basic land cards.
• Maular, the Next Evolution: creature cards with mana value 7 or greater of any color identity, and any basic land cards.
• Valko Indorian: Phyrexian cards of any color identity (the creature type, as the release notes say, never Phyrexian mana symbols), and any basic land cards.
• The Everforger: artifact creature cards and Equipment cards of any color identity, and any basic land cards.
• The Unluckiest Planeswalker: Aura cards of any color identity, and any basic land cards.
• Grizzlegom, Hurloon Hero: any land cards.
• Tolabow, Loch Rascal: instants and sorceries may have one color of your choice beyond the commander's, and any basic land cards. The page reads the color from the deck: the one extra color used by the most copies of its instants and sorceries (a tie goes to the color that came into the deck first). An instant or sorcery with any other extra color, or with two, is flagged, and the side panel shows every extra color the deck uses with its count.
• Whtz, the Bibliophile: no maximum deck size, so the format's exact count (100 in Commander) becomes the least the deck can have (a 163-card deck reads "163/100+").

A card's kind is the kind it has in the library: a split card and a Room count both halves, any other two-part card only its front (an adventurer is its creature, a double-faced card its front face). Mana value is Scryfall's. Changeling works everywhere, even outside the game (CR 702.73a), so a changeling card, and Mistform Ultimus, is an Angel card for Seluma and a Phyrexian card for Valko; never an Aura or Equipment card, which aren't creature types.

What still applies. As the release notes say, a rulebreaker counts only while the card is your deck's commander (a copy in the main deck changes nothing), only before the game, and changes no deck rule it doesn't name: one copy of each card, the banned list and format legality all still apply, and so does the deck size, Whtz aside. It applies in every commander format (Commander, Duel Commander, Pauper Commander, PreDH, Tiny Leaders, Brawl, Standard Brawl and Competitive Brawl), and in Oathbreaker for the oathbreaker (Oathbreaker's rule 906.14: a rule or effect that refers to your commander refers to your Oathbreaker), not in Captain. Two commanders can each bring one. A card outside the commander's colors that a rulebreaker lets in is listed under "lets in", never flagged; one it doesn't cover is flagged with the rule in words. A rulebreaker line the page can't read is said, and the deck is checked by the usual rules. The set's cards numbered 1 to 60 (its new cards) join Commander on November 13, 2026, and Legacy, Vintage and Duel Commander on January 1, 2027 (Wizards, What's Inside Mystery Booster Commander Edition; the Duel Commander committee, September 28, 2026); until then each reads "Joins Commander on November 13, 2026". The set's playtest cards are legal only in Mystery Booster Limited events, so a playtest rulebreaker is marked as needing your playgroup's yes.

• Mystery Booster Commander Edition release notes (Wizards, August 3, 2026)

Combos in the deck

Every Commander Spellbook combo (see the card pages) is checked against the whole deck, command zone included and maybeboard left out. In the deck: every named card is there; some also need one more card of a kind (a card that gives indestructible, say), which the combo names when opened. One card away: all but one named card is there, and that card is legal in the deck's format and inside its color identity when it has a commander. Most played first. The header chip counts both.

The castability dot

In the simulated games where you have enough mana on the card's turn, on the play, how often you can also pay its colors, counting every mana source in the deck (Manabase+'s engine, with London mulligans). That conditional is Frank Karsten's own measure. Green is at or above his bar; yellow is up to 8 points under it; red is more than 8 points under. His bar rises one point per turn:

dot = games where the colors are right / games with enough mana, on the play

bar = 89% + turn, up to 99% (a 1-drop needs 90%, a 4-drop 93%)

The quick first pass, shown while the full engine runs, counts lands only over 3,000 games and divides by the games with enough lands, the way Karsten's tables do.

Karsten's land count

From Frank Karsten's 2022 regression of land counts in real decks:

60 cards: 19.59 + 1.90 x average mana value - 0.28 x cheap draw or ramp spells (+0.27 with a companion)

99 or 100 cards: 31.42 + 3.13 x average mana value - 0.28 x cheap draw or ramp spells

Cheap means mana value 2 or less, counting card draw, ramp and card selection. Any deck of 38 to 42 cards gets 17, the Limited standard.

Commander bracket

The lowest bracket Wizards' published card rules allow, shown with every card that sets it:

• Any Game Changer: Bracket 3 at least. Four or more: Bracket 4.
• Any extra-turn card: Bracket 2 at least. Extra turns that loop or chain: Bracket 4.
• Mass land denial, or a two-card combo that denies lands: Bracket 4.
• A two-card combo that loops forever or wins on the spot: Bracket 3 at least.

It is a floor, not a power score: brackets also ask how fast a deck wins and what it's for.

• Introducing Commander Brackets Beta (February 11, 2025)
• Brackets update, April 22, 2025
• Brackets update, October 21, 2025
• Brackets update, February 9, 2026
• Banned and restricted announcement, October 12, 2026 (no Commander section; with the March 23, May 18, June 29 and August 10, 2026 announcements, read October 21, 2026: no bracket change after February 9, 2026)
• Wizards' Commander format page (Game Changers list, checked against Scryfall on every build)

The rule zero card

A shared Commander deck's page (/d/) shows a rule zero card under the deck: the same reading as the bracket above, made by the same code, so the two always agree. It lists the bracket floor and what could push it higher, the Game Changers, the two-card combos (eight at most, then a count), mass land denial, extra turns and tutors (cards whose role is a tutor, land searches left out, listed for the talk though tutors stopped being a bracket rule on October 21, 2025). Only the cards travel in the link; everything else is read on the page from the site's own data. It shows for a deck in the Commander format that has a commander.

Suggestion links

On a shared deck's page anyone can suggest changes without an account: cards to add by name, cards to cut by tapping them, a why for each and their name. Nothing goes to a server: the changes ride in the link itself, after the deck's own code (/d/#<deck>&s=<changes>), packed with the browser's own deflate and written in the address's safe letters. The page shows the result before the link is copied: the card count, lands, average mana value and the curve before and after, and the price change at each card's lowest paper price on the site's price day. A link longer than 1,900 characters is said to be too long for one Discord message (2,000 at most), and one past 2,953 too long for a QR code; links past 16,000 characters aren't made. Opened, the link marks every change on the deck; Review in Decks opens the same changes in your saved deck.

Embeds and card links for other sites

A deck's page makes an embed: an iframe of /e/#E<code> that shows the list with each card's picture on hover and a link back. Its code carries the names, counts, costs, types, picture ids and artists, so the page that frames it never loads the site's card list. Only /e/ may be framed. The autocard script (/autocard.js) turns [[Card Name]] on another site into a link to the card's page here, its picture read from the small file the card page itself starts from.

Sample hand

A seeded shuffle (the mulberry32 generator): the same seed always deals the same hand, so a hand can be replayed or shared. Play or draw follows the rules: in a two-player game whoever plays first skips their first draw; in multiplayer, nobody does (rule 103.8c).

Prices

TCGplayer market prices in US dollars, from Scryfall's printing file (read October 22, 2026), refreshed from Scryfall once a day for the printings in the deck when it opens. Every figure says which date it is from.

Which printing. By default each card is priced at the printing and finish the deck names (a list imported with set codes names them; so does picking one in the card's details). A printing made in one finish only is priced in that finish (a foil-only Secret Lair named with no finish is priced as the foil it is). A card with no printing named, or with no price for that printing and finish, is priced at its cheapest printing: the lowest price, any finish, among its printings you can play in a paper game (memorabilia, token, oversized, gold-bordered and playtest printings left out), serialized printings and printings whose TCGplayer and Cardmarket figures are more than twentyfold apart aside, printings already out before ones not out yet, ties going to nonfoil and then the newer printing. A card with no price on such a printing has no price here: it is never priced at, or sent to a store as, a Collectors' Edition or 30th Anniversary printing. When the printing priced isn't in English, its basis says the language. Switch "price by" to cheapest printings to price every card that way. When the two ways differ, the price and buy tab shows both figures. The deck list prices every deck at its cheapest printings (a list of many decks doesn't read every printing file), and says so.

deck value = sum over the main deck, sideboard and commander of copies x price each

still to buy = sum of (copies - copies you own) x price each, never below zero per card

What's counted. The main deck, sideboard and commander. The maybeboard is shown apart and never in a total. Cards you mark as proxies in the deck are left out, and basic lands are left out unless you tick "count basic lands". A card with no price on a printing you can play is listed and left out of the totals; a card that was never printed on paper (an Arena card) is listed as not sold.

What you own. Paper copies in your collection, since stores sell paper cards (Arena and Magic Online copies are shown, never counted as owned here), plus your proxies when the deck's settings count them. Copies you own go to the commander first, then the main deck, then the sideboard. A copy your other decks also list counts for this deck too, and the price and buy tab names those cards and decks; tick "set aside copies my other decks list" to count only the copies left after the other decks' counts (paper decks and decks with no platform set). The row badges in the deck lists count copies where the deck is played: Arena copies for a deck marked Arena only.

On Magic Online. The price and buy tab also prices the deck in tix: each card at its cheapest Magic Online price, the lowest of its paper printings' tix (Cardhoarder via Scryfall, in the printing file) and of its printings made only for Magic Online (Vintage Masters, Tempest Remastered, the Masters Editions, MTGO promos: cards/mtgo_tix.json, dated). Basic lands and proxies are left out, as in the paper price; a card with no tix price is named and left out of the total. A deck played on MTGO, and every Penny Dreadful deck, shows the total in its side column.

Where the store links go

Links only: the site never asks a store for anything. Each link opens the store's own public page in a new tab, and none carries an affiliate or partner code. mtgstuff isn't affiliated with TCGplayer or Card Kingdom and earns nothing from them.

• TCGplayer, one printing: its product page, tcgplayer.com/product/<product id>, with the product id Scryfall publishes for that printing (the same page Scryfall's own links open); the foil link adds Printing=Foil. TCGplayer sells an etched foil as its own product, so an etched link goes to that product's id (Scryfall's tcgplayer_etched_id). A printing with no product id on file gets TCGplayer's search for the card instead.
• TCGplayer, every printing: its product search for the card's name.
• TCGplayer Mass Entry: tcgplayer.com/massentry?productline=Magic&c= with one entry per card, joined by ||, in TCGplayer's own share-link format: 2-<product id> for the exact printing priced on the page, or 2 Card Name to let TCGplayer match any printing. An etched foil goes by its etched product's id. A card with no price on a printing you can play goes by name. A very long list is split into parts.
• Card Kingdom: its catalog search for the card's name (every printing it stocks; Card Kingdom's printings can't be matched to Scryfall's one by one from here), and its deck builder, cardkingdom.com/builder, sent the list as a form with one 2 Card Name line per card.
• Names: stores list a split card (Fire // Ice, aftermath cards, Rooms) by its whole name and a two-faced, adventure, flip or prepare card by its front face, so that's how the site writes them. The copy-the-list button uses the same names for any other store.

Honest records

A record is wins and losses; a win rate is wins over wins plus losses. Draws are shown beside it and never counted as half a win. Every win rate carries its 95% range, from the Wilson score interval, the one that stays honest at small sizes (a 3-0 start doesn't read as 100%):

range = (p + z^2/2n +/- z x sqrt(p(1 - p)/n + z^2/4n^2)) / (1 + z^2/n), with z = 1.96

where p is the win rate and n the decided matches. The bar draws the rate as a tick and the range as a band on a 0 to 100% scale, with 50% marked. Under 20 decided matches the record says "small sample". A difference between two records (on the play against on the draw, one version against the one before) carries Newcombe's range for a difference of two rates (his method 10, built from the two Wilson ranges), and says where that range sits: "higher" when the whole range is above zero, "lower" when it is all below zero, and "can't tell apart at this sample" when it includes zero:

difference range = d - sqrt((p1 - l1)^2 + (u2 - p2)^2) to d + sqrt((u1 - p1)^2 + (p2 - l2)^2), where d = p1 - p2 and l, u are each rate's Wilson range

Games won and lost come from the games you entered (2-1 is two games won, one lost); games inside a match aren't independent, so the match record is the one to trust. Each match says where it came from: Arena log when Film Room read it from your Arena log, by hand when you logged it. Changing a Film Room match's result by hand makes it a hand-logged match. Matches are stamped with the deck version they were played with: the number of versions saved before the match's date.

Sources: E. B. Wilson (1927), "Probable inference, the law of succession, and statistical inference", Journal of the American Statistical Association 22; R. G. Newcombe (1998), "Interval estimation for the difference between independent proportions: comparison of eleven methods", Statistics in Medicine 17; Evan Miller, "How Not To Sort By Average Rating" (evanmiller.org), for why the library sorts records by the low end of the range.

Share links and records

A share link leaves your record out unless you tick "include the record" (up to the latest 300 matches). It then carries, per match: the day, their deck, the result and games, play or draw in game one, best of one or three, where, the version, and whether Film Room read it from an Arena log. Notes never travel. The person opening the link sees the record read-only and labeled as yours; saving a copy starts their own record empty. A link can be edited by anyone who has it, so a shared record is your word, not proof, until accounts can vouch for records.

The precon shelf

2,877 preconstructed decks and fixed-content products from MTGJSON's deck files (MIT license), file of 2026-10-18: Commander decks, Challenger decks, Secret Lair drops, Jumpstart themes, starter, theme, intro and planeswalker decks, Arena starter decks and the rest. Left out: MTGJSON's MTGO Redemption lists (whole sets listed for Magic Online's set redemption, 198 in the October 18, 2026 file) and the Shandalar decks (a video game's computer opponents, 55), since nobody opens or builds from them. The site keeps each deck's name, set, kind, release day, commanders and sealed products, and its cards with the exact printing (Scryfall id) and finish MTGJSON lists, in files of about 150 KB, so opening one reads one file.

How a precon is priced. It opens as an unsaved deck in the printings and finishes the product holds, so the deck value is its cards at today's single prices by the price rule above (basic lands left out unless you count them), not a sealed price: no source the site may use publishes sealed prices. What you own shows as on any deck. Planes, schemes and anything the site's card list doesn't hold (sticker sheets, Alchemy cards) stay out, and the page says how many. Commander decks open under Commander, Historic Brawl precons under Brawl, and Throne of Eldraine's 60-card Brawl decks (made when Brawl was today's Standard Brawl) under Standard Brawl; a double-sided Secret Lair card or a meld card is read as its front face; Challenger decks under Standard (Pioneer Challenger decks under Pioneer), the Modern Event Deck under Modern, everything else as Casual; the format can be changed. "Save a copy" makes it your own deck.

From a sealed product. Collection's sealed tab names a product by the first 12 hex digits of MTGJSON's product id, and MTGJSON lists, for each deck, the sealed products it comes in. A product with one deck opens it; one with several shows those decks on the shelf. Of the 1,960 product ids the precons name, 1,920 are in Collection's sealed list (MTGJSON's September 30, 2026 file).

What can I build

Your saved decks (retired ones aside), the precons of the kind you pick, and Meta Lens's typical list for each archetype of the format you pick, each set against your Collection, read only. Basic lands are left out of every count. A commander format's sideboard isn't part of the deck, so it never counts; other sideboards count while "count sideboards" is ticked. A list with nothing left to count (a land pack, or cards the site doesn't list) is left out, and the count says how many.

Copies you own. Paper: every copy in your collection, less the copies in Arena and Magic Online binders; proxies and wishlists never count. Arena: the copies in your Arena binders or the Arena collection Wildcard Planner holds, whichever says more. A copy your other decks list still counts as owned here.

share owned = sum over cards of min(copies needed, copies you own) / sum of copies needed

dollars to finish = sum over cards of max(0, copies needed - paper copies you own) x cheapest printing price

wildcards to finish = for each card, max(0, copies needed - Arena copies you own), by its craft rarity

The share is shown rounded down to a whole percent. The cheapest printing price is the site's price rule (the prices section); a missing card with no price is counted and named, never priced at zero. Craft rarity is Wizards' lowest-rarity rule, from cards/arena.json, the data Wildcard Planner reads; a card not on Arena is counted apart. Sorting: share owned, most first (ties: fewer dollars); dollars to finish, least first (ties: more owned); wildcards to finish, lists with a card not on Arena last, then fewer mythic and rare wildcards, then fewer of all four.

Which Meta Lens archetypes. Those with 3 or more published lists in the last 30 days of Meta Lens's data (a window ending at the newest event it holds, data read October 22, 2026), "Other" and "Unknown" aside. Each typical list is built by Meta Lens's own rule: cards in order of how many lists play them, each at its most common count, until the median main deck and sideboard size, within each card's copy limit.

Card packages

A named group of cards kept in this browser (under "packages"): up to 400 lines, each a card, a count from 1 to 999 and a board. A pasted list is read by the importer's line reader: "4 Name", "4x Name", "Name x4", the set code, number, finish or category other apps write after a name ("1 Sol Ring (C21) 263 *F*", "[Ramp]"), "(sideboard)" or "(maybeboard)" at the end, or a Sideboard or Maybeboard heading; a name the site doesn't know is said and never guessed, and the same card twice is added up. Adding a package to a deck puts each card in at its count, in the board it names or the one you pick, skips a card already in the deck unless you say otherwise, can group them under the package's name, and is one change with one undo. "Whole in" counts your saved decks (the open one aside) holding every card of it, maybeboards aside. A package's link carries the name and the lines, compressed in the address after #pk=, nothing uploaded; whoever opens it sees the list and saves it only if they choose.

Several decks in one link

A folder, a gauntlet or a playgroup's decks in one link (/d/#m...): the group's name (80 characters at most), an optional byline, and up to 50 decks, each in the short form a share image's QR code uses: its name, format, the day, and each card as a 4-byte fingerprint of its name (FNV-1a) with its count and board, a card the site doesn't know or a fingerprint two cards share going by its full name. Printings, primers, sideboard plans, records and the look stay out, to keep the link short; the whole is compressed (deflate). The dialog shows the link's length and warns past 1,900 characters (Discord takes 2,000 in a message); a group past about 190,000 characters gets no link, since links that long aren't opened. The page lists the decks; #m...~n opens deck n with a way back to the list, and its Copy link shares that deck alone. "Save all to my decks" saves them once into a folder named after the group (a slash in the name becomes a hyphen, so it doesn't nest).

Compare

The compare tab sets the deck beside other lists. Closest lists: the main deck is measured against every published list in its format from the window picked (Meta Lens's MTGO lists, the same data Meta Lens reads; a window like the last 30 days ends at the newest event in that data):

overlap = sum over every card of the smaller count / sum over every card of the larger count

A card missing from one list counts 0 there. Basic lands count like any card, and a card is matched by name, whatever the printing. 100% is the same main deck; 0% shares no card. The sideboard (in Duel Commander, the commander) is measured the same way, apart, and doesn't change the order. Ties go to the newer list. The ten closest are shown, each with its archetype, player, event, date and finish, and the cards that differ both ways with both counts. The source sometimes records one MTGO event under two addresses; Meta Lens keeps it once, by its tournament number, and a list that still repeats (the same player's same cards at the same event name, day and finish) is shown once.

An archetype: every list Meta Lens files under that archetype in the window. "In 31 of 34" counts the lists with at least one copy in that part of the deck; the average is the copies in those lists divided by the number of those lists. The add button adds the count most of those lists play (a tie goes to the larger count). These counts are Meta Lens's own, so the two pages agree: an event the source records twice counts once on both. The archetype shown first is the one most of the closest lists belong to.

Your decks: the other decks saved in this browser, measured the same way, and a card by deck table with the cards whose counts differ first. Nothing is sent anywhere: the lists are read into the page and every count is made in your browser.

Deck box labels

The QR code is made in your browser (qrcode-generator by Kazuhiko Arase, MIT license) at medium error correction, which reads with about 15% of the code scuffed or covered; a very long link drops to low correction rather than fail. A code scans easily when each of its little squares is at least half a millimeter wide, and with most phones down to about 0.38 mm, so the label shows that size for the code you picked:

square size = code width / (squares across + 8 for the quiet border)

The list, on any phone carries the deck in the link itself: its name, format, and each card as a 3-byte fingerprint of its name (FNV-1a, cut to 24 bits) with one byte for the count and board. The page that opens rebuilds the names from the card list. A fingerprint two cards share, or a card the site doesn't know, travels as its full name, so a card is never read as a different one. This deck, in this browser is a short link to the deck as saved here. Label sheet positions follow Avery's published templates for 5160, 5163 and 8371; the print page is set for no margins, so turn off the browser's own scaling and margins when you print.

The registration check

Reads the deck the way the printed list shows it. Counts and copy limits come from the format rules Decks already uses, main deck and sideboard together; a format with its own counts (Canadian Highlander and Gladiator: 100 cards and no sideboard; Tiny Leaders' sideboard of 10) is checked by them, and a Highlander deck's points against its cap with the list's date. Legality is Scryfall's, as of the card data's date. Paper status comes from the card data plus Arena's digital-only list; Arena names come from Scryfall's Through the Omenpaths names (MTR 3.6 counts both names as the same card). Each finding cites the Magic Tournament Rules (February 27, 2026), the Infraction Procedure Guide (September 23, 2024) or the Comprehensive Rules in our own words. A decklist problem is a game loss (IPG 3.4); a deck that doesn't match its list is a warning (IPG 3.5). The check never blocks printing.

Game by game

A best-of-three match can be logged game by game: each game's result and whether you were on the play. Game one is before sideboarding, later games after. The seats after game one are filled in as the loser of each game choosing to play (MTR 2.2), and any can be changed. Records then show each phase and seat as wins over games, with 95% Wilson ranges; Prep's best-of-three calculator reads the same four counts.

History

Decks keeps one version per editing session on its own: the version is brought up to date 90 seconds after the last change, when the page is hidden or left, and when the history is opened; half an hour with no change starts the next session. Before a big change (edit as text, a restore, a friend's suggestions, a budget pass) the list as it is is saved as a named version first. Versions kept on their own past 60 are thinned from the oldest; named versions and the box's never are. Everything stays in this browser.

Budget pass

For each card above the price you pick (the cheapest printing's price, with its date), the candidates are cards that share two of its Scryfall Tagger oracle tags, or its one tag when it has only one (functional tags only), do the same first job in the card facts' roles, are cheaper, are legal in the deck's format, fit its colors and are the same kind of card. Cards you own come first, then the ones sharing its rarest tags, then the lower price. It lists facts; which to play is yours.

Format guess and the name

An import with no format chosen is read for its shape: a 100-card singleton with a commander is Commander (Brawl when it came from Arena); otherwise the narrowest format every card is legal in, by Scryfall's legality, said as a guess with the card that decided it. A list of 40 to 45 cards with no commander is Limited; 50 cards with one commander is Tiny Leaders; among formats of the same shape the first where every card is legal is taken (an Arena Brawl precon is Brawl). When every card is legal and only the size is off, the guess says the size. The name is the list's own title, else the file's name, else its commander, else the archetype of the closest published lists (Meta Lens, weighted overlap of at least 50%, colors equal), else the archetype rules meta.py writes from those lists, else the first spell. An import is marked played on Arena only when it is unmistakably Arena's export (a Deck header and every card line in Arena's form with a set code Arena has); a list that only looks like one is asked about.

Compare with any list

Overlap is the copies two main decks share over the copies in either (for each card the smaller count over the larger, summed), basic lands included; the sideboard is measured apart. A precon's list is MTGJSON's (MIT License); a Meta Lens typical list is each card most of the archetype's lists in its last 30 days play, at its most common count.