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

Deck building

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 that appears below the search bar without having to open the filter menu.	["type", "cost", "aspects"]
costCurveIgnoredTypes	[]	optional	Card types excluded from the 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.	{ "Standard": { ... } }

"deckBuilding": {
  "mainFilters": ["type", "cost", "color"],
  "formats": [
    { "title": "Constructed", "gameplay": "Standard" },
    { "title": "Limited", "gameplay": "Standard" }
  ]
}

A format doesn't need a ruleset

deckRuleset and deckRulesets are both optional. Some games define two formats that share the same gameplay block and skip deck-building restrictions entirely.

Formats

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.	"Standard format"
customCategories	[]	optional	Deck categories specific to this format (e.g. a separate "Extra deck" or "Leader" 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 determines the gameplay used when playing with this deck	"Standard"
deckRuleset	S	optional	Must match a key under deckBuilding.deckRulesets. Omit if the format has no ruleset restrictions.	"Classic"

{
  "title": "Constructed",
  "legalityCode": "STD",
  "gameplay": "Standard",
  "deckRuleset": "Standard"
}

Reusing a gameplay block across formats

Several formats can share one gameplay block. If "Constructed", "Historic" and "Legacy" only differ in which cards are legal, give them the same "gameplay": "Standard" and "deckRuleset": "Standard", and vary only title and legalityCode. No need for a new gameplay block per format when the match rules are identical.

Deck rulesets

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	An array of card types or custom categories to which specific rules apply (e.g. exactly 1 to 2 Leader cards).	[ { "category": "Leader", "min": 1, "max": 2 } ]

"deckRulesets": {
  "Limited": {
    "general": { "min": 40, "maxPerCard": 4 },
    "categories": [
      { "category": "Sideboard", "min": 0, "max": 15 }
    ]
  }
}

Continue with Gameplay → or Sections & layout →.