The Deck Builder is a visual tool built with the interface of MTG Arena as a template. Adding cards is done by clicking cards from the search results. Changing the number of cards in the deck is done by clicking the quantity number for adding more, clicking the card name to subtract quantity and "x" to remove the card.
The URL Importer can be used to import partial or complete decks from external sites by using GET variables in the URL Address field of the browser. Cards can be imported to both the main deck and sideboard. Only decks with cards in the main deck will be imported, if only the sideboard is presented it will be ignored. The maximum cards in the main deck are 100 while the sideboard can contain a maximum of 15 cards. For Commander decks, there should be a maximum of 99 unique cards in the main deck while the Commander(s) should be in the sideboard. If you import a Commander deck with 100 cards in the main deck it will be deemed illegal by our legality checker. The reason for separating this is that we can perform advanced checks on your deck based on what Commanders we find in the sideboard.
The same is true for Brawl, maximum 59 unique cards in the main deck and Commander in the sideboard.
Example URL of a deck with 4 Goblin Guides and 20 Mountains in the main deck and 4 Shock in the sideboard. Cards are separated by newline:
URL encoding has to be used when sending in a decklist, this means Space is converted to "%20" and Newline converts to "%0A" as seen in the URL above. If the Deck Importer can't find one of the names specified in the list it will report an error with what I could not find and import the ones it find. For split cards like "Connive // Concoct" the builder only takes the first card name, in this scenario "Connive".
List of variables
|m||Main deck: all cards for the main deck goes here. Maximum 100 unique cards|
|sb||Sideboard: all cards for the sideboard goes here. Maximum 15 unique cards|
|comp||Companion: Used for settings companion. Only 1 card allowed|
|t||Type: Only option available is "cmd". If importing a Commander/Brawl deck this option should be used, it renames the Sideboard to "Commander". If this is not specified it defaults to "Sideboard"|
The Deck Builder can autoload a set when opening the page when using the variable "set" in the url and then the set name. Example of this: