Block Constructed (also known as Block) was a format that allows for cards of a chosen block to be played, save any banned cards. The format was abandoned as a competitive format after 2014, and Wizards of the Coast no longer supports Block in general as the block system itself was discontinued in 2018.
Constructed decks must contain a minimum of 60 cards. There is no maximum deck size; however, you must be able to shuffle your deck with no assistance. If a player wishes to use a sideboard, it must contain exactly 15 cards.
With the exception of card named Plains, Island, Swamp, Mountain, and Forest, a player’s combined deck and sideboard may not contain more than four of any individual card, counted by its English card title equivalent. Snow-covered lands, despite being basic lands, are only permitted in formats that allow the Ice Age block to be used. This similarly applies to Wastes in Battle for Zendikar block.
The intention of Block was to give players a glimpse of the format after rotation, with the players working with the cards that would stay around. In practice, it tended to be a futile exercise: staples were printed with rotation in mind, hence some formats had core pieces missing that would never be missing in any Standard, a cycle of dual lands being missing epitomizing this issue. If the current block was too weak, the next block informs the Standard format and the decks shown are quaint; if the current block is too strong, the decks on display are going to be prevalent ad nauseum: neither were desirable and rarely was there middle ground.
According to Mark Rosewater, Block has proven over time to be an unpopular format almost exclusively played because Wizards of the Coast required it at Pro Tours and Pro Tour Qualifiers. He stated that it was being phased out because players almost never played it of their own volition. The format itself was dropped on the same day Dominaria, the first set of Three-and-One Model (in which blocks are no longer used), released.
Blocks that were DCI sanctioned but never used in a Pro Tour and/or Grand Prix.
- Ixalan block (Ixalan, Rivals of Ixalan)
- Amonkhet block (Amonkhet, Hour of Devastation)
- Kaladesh block (Kaladesh, Aether Revolt)
- Shadows over Innistrad block (Shadows over Innistrad, Eldritch Moon)
- Battle for Zendikar block (Battle for Zendikar, Oath of the Gatewatch)
- Khans of Tarkir block (Khans of Tarkir, Fate Reforged, Dragons of Tarkir)
Blocks that had been used in at least one Pro Tour and/or Grand Prix.
- Theros block (Theros, Born of the Gods, Journey into Nyx)
- Return to Ravnica block (Return to Ravnica, Gatecrash, Dragon's Maze)
- Innistrad block (Innistrad, Dark Ascension, Avacyn Restored)
- Scars of Mirrodin block (Scars of Mirrodin, Mirrodin Besieged, New Phyrexia)
- Zendikar block (Zendikar, Worldwake, Rise of the Eldrazi)
- Alara block (Shards of Alara, Conflux, Alara Reborn)
- Lorwyn–Shadowmoor block (Lorwyn, Morningtide, Shadowmoor, Eventide)
- Time Spiral block (Time Spiral, Planar Chaos, Future Sight)
- Ravnica block (Ravnica: City of Guilds, Guildpact, Dissension)
- Kamigawa block (Champions of Kamigawa, Betrayers of Kamigawa, Saviors of Kamigawa)
- Mirrodin block (Mirrodin, Darksteel, Fifth Dawn)
- Onslaught block (Onslaught, Legions, Scourge)
- Odyssey block (Odyssey, Torment, Judgment)
- Invasion block (Invasion, Planeshift, Apocalypse)
- Masques block (Mercadian Masques, Nemesis, Prophecy)
- Urza's block (Urza's Saga, Urza's Legacy, Urza's Destiny)
- Tempest block (Tempest, Stronghold, Exodus)
- Mirage block (Mirage, Visions, Weatherlight)
- Ice Age block (Ice Age, Homelands, Alliances)
- Despite Homelands being replaced by Coldsnap in July 2006 for Ice Age block, Coldsnap itself was never actually used in Block's Pro Tour/Grand Prix events.
- Æther Vial
- Ancient Den
- Arcbound Ravager
- Darksteel Citadel
- Disciple of the Vault
- Great Furnace
- Seat of the Synod
- Tree of Tales
- Vault of Whispers
- Gaea's Cradle
- Memory Jar — The only card to have been the subject of an emergency ban in the format.
- Serra's Sanctum
- Time Spiral
- Tolarian Academy
- Voltaic Key
Ice Age block
- Amulet of Quoz
- Thawing Glaciers
- Timmerian Fiends — Removed from banlist when Homelands was replaced by Coldsnap in the format.
- Zuran Orb
- Sam Stoddard (May 17, 2013). "Building Blocks". magicthegathering.com. Wizards of the Coast.
- Reid Duke (April 27, 2015). "An Introduction to the Popular Constructed Formats". magicthegathering.com. Wizards of the Coast.
- Mark Rosewater (September 05, 2015). "Will the new 2-set system lead to more instances of or support for Block Constructed events?". Blogatog. Tumblr.