List of unreleased mechanics

There are some mechanics that have been designed by R&D but have been never released for several reasons as rules concerns. Some of them have been publicly explained over the years.

Unreleased colors

• Purple — For Planar Chaos.

Unreleased keyword actions

• Double-tap — For Time Spiral. Cards that could tap, then tap again. Led to exert.
• Hedronize — For Battle for Zendikar. Roll a d8 and trigger a different effect depending on the value rolled.

Other unreleased mechanics

• "Artifactfall" — for Kaladesh. Effects that trigger whenever an artifact you control enters the battlefield.
• Advocate — for Commander Legends. A triggered mechanic (like landfall or constellation) that triggers whenever your commander enters the battlefield or attacks.
• Anchor — For Time Spiral. Big creatures for cheap that required a mana payment for upkeep.
• Bribe — for Conspiracy: Take the Crown and Commander Legends. The spell gives you an effect. Then, each of your opponents may choose to draw a card. For each one that did, you get the effect again.
• Call — for Ixalan. A Dinosaur with call was usually a bigger Dinosaur, but one with a very cheap mana cost. You couldn't attack or block until you paid a one-time activation cost.
• Camouflage (As long as this is untapped, it can't be the target of spells or abilities your opponents' control) for Ikoria: Lair of Behemoths. This is similar to Paradise Druid.
• Cartel — For Streets of New Capenna. A creature version of metalcraft (spells that got an upgrade if you controlled three or more creatures).
• Celestial (You may cast this card from Nyx. If it would enter the battlefield any other way, it goes to Nyx instead. If the card would leave the battlefield, it goes to Nyx instead. Your devotion to white reduces its cost by that much N) for Theros.
• Clan — for Kaldheim. A modified version of Leader adapted for use as a tribal mechanic. When you played a clan card, you chose a creature type, and the card affected that creature type. Then when you played a second clan card, you could rechoose your creature type, but both effects would affect the one chosen tribe.
• Conjure [creature type] – [cost] — for Strixhaven: School of Mages (If you cast this spell for [cost], when it enters the battlefield create an [appropriately sized, colored, and creature-typed] creature token.)
• Cooperation (Whenever this creature deals combat damage to a player, put a +1/+1 counter on another target creature.) for Throne of Eldraine. A variant of the Slith mechanic.
• "Deathfall" — for Jund in Shards of Alara. Effects that trigger every time a creature dies.
• Debt — for Orzhov in Ravnica Allegiance. Spells give debt counters to opponents. At the beginning of their end step, they can get rid of any number of debt counters by paying per debt counter. Then, as long as they have any debt counters remaining, they lose 1 life (not per debt counter just 1 life total regardless of how many debt counters they have).
• Discipline N (Whenever this card becomes blocked, put N +1/+1 counters on this card.) for Throne of Eldraine.
• Disguise — for Dimir in Guilds of Ravnica. A ninjutsu variant where the creature with disguise is swapping with the attacking creature.
• Endless — for Future Sight. A keyword that made the creature return to your hand whenever it went to the graveyard from the battlefield.
• Enhanced — for Kaldheim. Enhanced meant that a creature was either enchanted or equipped. The ability went on creatures and gave them an extra ability if they were enhanced. Later reworked into modified.
• Enlist — for Ixalan. Pay extra mana to create a creature token.
• "Enter the Upper City" — For Battle for Baldur's Gate. Loosely inspired by King of Tokyo-esque battles for dominance and the three-tiered structure of Baldur's Gate itself. Through combat and keyword actions, players would move up or down a map of the city, accruing rewards for elevating their status to the top and maintaining it there at the expense of other players.
• Familiar – [Effect] — for Strixhaven: School of Mages (. . . if you control a creature token).
• Finale — For Rakdos in Ravnica Allegiance. The creature gains +N/+0 and some abilities, in exchange for being sacrificed at the end of turn.
• Floating — By Mark Gottlieb, for Commander (2011). Appeared on creatures and allowed you to summon creatures under another player's control and they would be unable to attack you. Inspired the cycle of Vow auras in Commander 2011.
• Forbidden — By Mark Rosewater, for Avacyn Restored. The card starts the game in exile.
• Glorify — For Amonkhet. If this creature dies when attacking, it grants a bonus to another creature.
• Gunk — By Richard Garfield. Blank cards that didn't do anything but could be transferred to the opponent's deck. It later appeared on a test card in the Mystery Booster set.
• Heft — the value of combined power and toughness.
• Hieroglyphics — By Mark Rosewater, for Amonkhet. Pay to exile the card from the graveyard and draw a card.
• Implements — for Strixhaven: School of Mages.. Artifacts with two different tap abilities (one in each color of the school) and a third ability which was the combination of the two abilities.
• Inventions — for Kaladesh. Getting things from outside your deck. It was like lesson/learn except that they were all artifacts rather than instants and sorceries.
• Jewel — For Guilds of Ravnica. It went on any instant or sorcery. After the card was resolved, it got exiled. Then, whenever you cast another instant or sorcery, you could play the first card for free from exile. The idea behind it was that we built smaller effects that combined to do cool things.
• Joust (When this creature is blocked, it gets +0/+N until end of turn. If not blocked, it gets +N/+0 instead.) for Throne of Eldraine.
• "Land drop" for Zendikar. : action (You may use land drop only if you haven’t played a land this turn. If you use land drop, you may not play a land for the remainder of the turn.)
• Leader — for "Salad", an unmade set intended to follow on from Dominaria. Whenever you played a leader card, you chose a leader from among your creatures, and that card granted an ability to your leader. If you played a second leader card, you had the option of changing who your leader was, but both cards would grant abilities to a single leader.
• Mechanic I — For Kaladesh. The Invention unreleased subtype (see below).
• Megaparty — For Battle for Baldur's Gate. Batching all the Class creature types.
• Mindhack — For Streets of New Capenna. It went on creatures, and it allowed you to have the creature enter tapped and get a looting effect (draw a card and discard a card).
• Mummify — For Amonkhet. As embalm or eternalize, but makes the creature a 2/2 Zombie with wither.
• Nostalgia — By Mark Rosewater, for Time Spiral. It allowed you to put Vintage-legal cards into your deck that you might not normally be able to play.
• Paincast — For Rakdos in Return to Ravnica. Spells 1 mana cheaper for each point of damage you had dealt to an opponent this turn.
• Plot — For Amonkhet. A suspend variant representing you planning ahead.
• Plunder — For the Vampires and Pirates of Ixalan. Based on bloodthirst. When you cast these cards, if you had dealt combat damage to an opponent, the card received some kind of bonus. Remained unkeyworded, but revisited as the Vampires' theme in Midnight Hunt.
• Precedence — For Azorius in Ravnica Allegiance. When this enters the battlefield, copy the ETB ability of any other creature you control.
• Reckless — For Gruul in Gatecrash. An ability that sacrificed the creature at the end of the turn when triggered.
• Relentless — For Time Spiral and inspired by Relentless Assault. Allowed creatures to attack twice each turn.
• Reverse Engineer — For Kaladesh but pushed for Aether Revolt. It allowed you to copy an artifact and then that copy got sacrificed at end of turn, in the same way Heat Shimmer from Lorwyn does for creatures.
• Roar — By Mark Gottlieb, for the Dinosaurs of Ixalan. "You may pay [cost] and exile this card from your hand. If you do, you can still cast it this game. When CARDNAME roars .... [effect]". Led to Adventure.
• Rumble — For Streets of New Capenna. A rider on spells that allows you to pay 2 life to get a 1/1 creature token.
• Showoff — By Mark Rosewater, for Lorwyn. It allowed you to choose to reveal a card. If the card was revealed (from your hand or your library), then it could be played for its showoff cost, which was often cheaper than its normal mana cost.
• Sift — for Dominaria United. Sift was a cycling variant that allowed you extra utility out of the graveyard. Sift COST (COST, Exile this card from your hand or graveyard: Scry 2. If it was exiled from your hand, draw a card.).
• Skilled / Feat — For Battle for Baldur's Gate. A Skilled Commander started the game with a feat from your deck. Feats were kind of a monstrous emblem that initially showed up on all the mono-color legendary creatures. You could pay their cost to permanently turn them on and grant your commander that ability for the rest of the game, even if it left the battlefield and returned. In addition, if your commander had the skilled ability, you could choose the feat of another card and put it into your command zone. Then once your commander was on the battlefield, you could spend the cost to permanently turn it on. Your commander having a feat added that color to your commander's color identity. Skilled creatures were allowed to use the feat that was on them.
• Smuggling — for Streets of New Capenna. A way to help with color fixing.
• "Sneaky" (This creature can't be blocked by creatures with power 3 or greater) for Ikoria: Lair of Behemoths.
• Spellback — for the Izzet League in Guilds of Ravnica. Somehow allowed players to "mix and match various instants and sorceries".
• Stopwatch — mechanic forces you to do certain actions in a set amount of time. Considered for Unstable, cut down to two cards.
• Spell-pair — For Battle for Baldur's Gate. A commander mechanic for enabling players to add color to their mono-color commander by starting the game with an instant or sorcery in the command zone that they could cast once per game, possibly under a specific condition.
• Study – [cost] — for Strixhaven: School of Mages. A mechanic where you can spend a resource (tapping at common, mana at uncommon) to add an ability to the card. Each card with study has two options of abilities to add. The second time you activate it, you can add the ability you didn't choose the first time.
• Stygian — for Theros Beyond Death. When you play a card with the stygian mechanic, it brings onto the battlefield a special card from outside the game that represents the river of the dead. Creatures on the living side could only block creatures also on the living side while creatures on the dead side could only block creatures on the dead side.
• Titan — for Zendikar Rising. A kicker variant where the mana cost was always generic and always seven or more mana. It tended to mega-juice the spell. The flavor was that you were tapping into some residual Eldrazi energy that was seeped deep into the land.
• Torment — Each opponent loses 3 life unless that player sacrifices a non-land permanent or discards a card. Reduced to an unkeyworded vertical cycle in Hour of Devastation.
• Turmoil — For Gruul, then Rakdos in Ravnica Allegiance. An effect that triggered at the end of your turn if an opponent had lost life during that turn.
• Unique — By Mark Rosewater, such a mechanic is intended to narrow the Legendary rule effect which would be applied only to legendary permanents having the Unique ability.
• Unnamed — By Mark Rosewater, for Tempest. It allowed you to choose to start with the card in your opening hand. If you chose to do so, you had to begin with one card fewer.
• Unnamed — For Amonkhet. It made use of -1/-1 counter to represent the ruthlessness of Bolas.
• Unite {{-)) for Dominaria United. A monstrosity variant flavored as two creatures teaming up. When you paid the mana to add +1/+1 counters, it also added color and a creature type.
• Valiance (Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.) for Throne of Eldraine. This is the Slith mechanic.

Unreleased lands

• Barry's Land — By Mark Rosewater, for Invasion. Later by Bill Rose, for Conflux. Printed as a test card in the Mystery Booster set.
• Cave/City — See Purple.

Unreleased card types

• Structures — designed by Richard Garfield for Ravnica: City of Guilds. The idea was that they represented buildings. Structures functioned a lot like enchantments or global artifacts, in that they had a static effect, but they had one difference — a toughness that the opponent could attack and whittle down. Elements of them went into making planeswalkers.

Unreleased subtypes

• Quest (other mechanic than the released Quest enchantment) — For Zendikar and Throne of Eldraine. Enchantments that gave you three tasks. You marked them with counters as you finished each one. Once all of them were completed, you could sacrifice the card for a big effect. Some got you the legendary artifacts for each court.
• Invention — for Kaladesh. Cards that let you fetch artifact cards from outside the game. The only unexplained mechanic of the five that the Kaladesh design team ended up making and liking. It got discarded for excess of mechanics.
• Scroll — for Strixhaven: School of Mages. The idea of scrolls was that they were artifact tokens that could hold an instant or sorcery in them. You then sacrificed them to cast the spell it was holding. Some cards let you make scrolls out of available instants or sorceries. Other cards made scrolls with spells (usually famous ones from Magic's past) already inside them.

Unreleased supertypes

• Über-classes — By Mark Rosewater, for Morningtide. Cards that affected "fighters" affected Soldiers and Warriors (and possibly Knights). "Mages" were Shamans and Wizards (and possibly Druids). "Scoundrel" meant Assassins and Rogues. Similar to the later batching.

Unreleased counters

• Volatile counters — By Mark Gottlieb, for Aether Revolt. When a card with a volatile counter dies, it deals 2 damage to target opponent.

Unreleased tokens

• Scroll tokens — for Strixhaven: School of Mages. Artifact tokens that had a spell “inside”. You could sacrifice them to cast the spell.

Revealed mechanics

These formerly unreleased mechanics were eventually used in new sets.

• Assemble — Printed on a single card in Future Sight, but without any associated mechanical definition. Released in Unstable.
• "Creaturefall" — for Selesnya in Guilds of Ravnica. Effects that trigger whenever a creature you control enters the battlefield. Released as Alliance in Streets of New Capenna.
• Last strike — By Mark Rosewater, for Future Sight. Released in Unstable.
• Link — By Ken Nagle, for New Phyrexia. Supposedly the same [Redacted] mechanic that Aaron Forsythe hinted. Released in Eldritch Moon as meld.
• Mechanic E — By Mark Rosewater. Mechanic E, "energy", was originally designed for Mirrodin and finally printed in Kaladesh as energy counters.
• Pwnage — By Ken Nagle, for New Phyrexia. It allowed you to shuffle cards from your opponent's library into your own. It was killed by the rules, but released as Praetor's Grasp.
• Q-mechanic — By Mark Gottlieb, for Shadowmoor. It became the untap mechanic ().
• Skirmish — for War of the Spark. "Create a Skirmish if one hasn't been created yet." The Skirmish token has a tiny "game board" on it showing a field of combat. When you perform one of the stated conditions, you advance on the field toward the opponent's side. If you have advanced enough, you win the skirmish. There is a payout for winning, a generated effect. Released in Dungeons & Dragons: Adventures in the Forgotten Realms as Venture into the dungeon.
• Triple strike — By Mark Rosewater, for Future Sight. Released in Unstable.
• Resistance (This creature isn't a legal target of a spell or ability an opponent controls unless they pay as that spell or ability resolves) for Ikoria: Lair of Behemoths. Led to Ward.