Deck building

Deck building panel

Everything under deckBuilding: which formats are offered when a player builds a deck, and what legality rules apply to each. This is the part of the file read before a match starts.

S stringN numberB boolean[] array{} object

deckBuilding

Everything that happens before a game starts: which formats are offered and how deck legality is enforced.

Field	Type	Required	Description	Example
mainFilters	[]	required	Filter names shown in the deck builder.	["type", "cost", "aspects"]
costCurveIgnoredTypes	[]	optional	Card types excluded from the mana/cost curve chart.	["Land"]
formats	[]	required	One entry per playable format. Each entry is a full object — see "formats[] entry" below.	[{ "title": "Standard", ... }]
deckRulesets	{}	optional	Dictionary of deck-building rulesets, keyed by name and referenced by formats[].deckRuleset. Optional — a format without a matching ruleset simply has no min/max enforcement.	{ "Classic": { ... } }

"deckBuilding": {
  "mainFilters": ["aspects", "type", "cost"],
  "formats": [
    { "title": "Premier", "gameplay": "Classic" },
    { "title": "Twin Suns", "gameplay": "Classic" }
  ]
}

A format doesn't need a ruleset

deckRuleset and deckRulesets are both optional. Star Wars Unlimited's file, for example, defines two formats that share the same gameplay block and skip deck-building restrictions entirely.

formats[] entry

Each element of deckBuilding.formats is a mode offered to the player, independent from the others.

One playable format, offered to the player when building a deck.

Field	Type	Required	Description	Example
title	S	required	Display name in the format picker. Give it a distinct name from the matching gameplay key to avoid confusion — e.g. "Standard format" rather than reusing "Standard".	"Standard format"
customCategories	[]	optional	Deck categories specific to this format (e.g. a separate "Extra deck" or "Commander" slot).	["Extra deck"]
legalityCode	S	optional	Code used to filter which cards are legal in this format.	"COR"
gameplay	S	required	Must match a key under the top-level gameplay object — this is what determines the game rules once the deck is built.	"Standard"
deckRuleset	S	optional	Must match a key under deckBuilding.deckRulesets. Omit if the format has no ruleset restrictions.	"Classic"

Reusing a gameplay block across formats

In the Magic: The Gathering example, Modern, Vintage, Standard, Legacy and Pioneer all point at the same "gameplay": "Classic" and "deckRuleset": "Classic" — only title and legalityCode differ. You don't need a new gameplay block for every format if the match rules are identical.

deckRulesets{} entry

Not an array — an object keyed by ruleset name, referenced by formats[].deckRuleset.

Construction rules referenced by one or more formats.

Field	Type	Required	Description	Example
checkCardLegality	B	optional	If true, checks that every card carries the format's legalityCode.	true
general.min / max	N	optional	Total number of cards allowed in the main deck.	{ "min": 60 }
general.maxPerCard	N	optional	Maximum copies of a single card allowed.	4
categories	[]	optional	Per-category rules (e.g. exactly 1 Coconut card). An array because a ruleset can constrain several categories at once.	[ { "category": "Coconut", "min": 1, "max": 1 } ]

"deckRulesets": {
  "Coconut": {
    "general": { "min": 61, "max": 61, "maxPerCard": 4 },
    "categories": [
      { "category": "Coconut", "min": 1, "max": 1 }
    ]
  }
}

Continue with Gameplay → or Sections & layout →.