Mnemonic Deluge — ruling 1

You create and cast the copies all during the resolution of Mnemonic Deluge. You can't wait and cast them later. If you don't cast all three copies, the ones you don't cast will cease to exist.

Mnemonic Deluge — ruling 2

Because you're casting the spells during the resolution of Mnemonic Deluge, ignore any timing restrictions based on card type. In other words, you can cast copies of a sorcery card this way.

Mnemonic Deluge — ruling 3

If you cast a spell "without paying its mana cost," you can't choose to cast it for any alternative costs. You can, however, pay additional costs. If the card has any mandatory additional costs, you must pay those to cast it.

Mnemonic Deluge — ruling 4

If the card you copy has {X} in its mana cost, you must choose 0 as the value of X when casting the copy without paying its mana cost.

Mnemonic Deluge : règles, fonctionnement et interactions (MTG)

Mnemonic Deluge is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Exile target instant or sorcery card from a graveyard. Copy that card three times. You may cast the copies without paying their mana costs. Exile Mnemonic Deluge.

Complete guide

Mnemonic Deluge is a high-impact blue sorcery that allows you to turn a single powerful spell in a graveyard into a triple threat. By exiling a target instant or sorcery, you gain the ability to cast three copies of it immediately, overwhelming your opponents with value. This nine-mana investment can easily end the game if you choose the right target.

What It Does

When Mnemonic Deluge resolves, you target one instant or sorcery card in any graveyard. You then create three copies of that card in exile. You have the choice to cast each of those copies without paying their mana costs, and finally, Mnemonic Deluge exiles itself to prevent recursion loops.

Resolution Step-by-Step

First, you choose a legal target in a graveyard. Upon resolution, the target card is exiled. Next, you create three copies of that card. You decide the order in which you cast these three copies. Since this happens during the resolution of a spell, you ignore normal timing restrictions, allowing you to cast sorcery copies even if it isn't your main phase. Any copies you choose not to cast will simply cease to exist.

Common Mistakes and Costs

A common mistake involves 'X' spells; if the exiled card has {X} in its cost, X must be 0 because you are casting it for free. Additionally, while you bypass the mana cost, you cannot use alternative costs like Delve. However, you are still responsible for mandatory additional costs, and you may choose to pay optional additional costs like Kicker.

When to Play It

Mnemonic Deluge is best played when you have a high-impact spell in your graveyard, or even an opponent's graveyard, that provides massive card advantage or board presence. Because it costs nine mana, it is a quintessential finisher for control or big-mana decks.

Interaction examples

Refilling Your Hand

Treasure Cruise

You target Treasure Cruise in your graveyard. Mnemonic Deluge exiles it and creates three copies. You cast all three copies for free, ignoring the Delve ability entirely. Each copy resolves to draw you three cards, resulting in a total of nine new cards in your hand.

Cascading Complexity

Aminatou's Augury

By targeting Aminatou's Augury, you create three copies of a spell that already lets you cast multiple spells for free. As each copy of Aminatou's Augury resolves, you exile the top eight cards of your library and potentially cast one card of each nonland type among them. Repeating this three times allows you to dig through 24 cards of your library and cast a massive portion of them without paying any mana.

Guide written with AI from the official text and rulings. Official English text prevails.

How it works : Mnemonic Deluge

Original English text — Wizards of the Coast / Scryfall

#1November 10, 2020· Wizards of the Coast
You create and cast the copies all during the resolution of Mnemonic Deluge. You can't wait and cast them later. If you don't cast all three copies, the ones you don't cast will cease to exist.
No other card is named in this ruling.
#2November 10, 2020· Wizards of the Coast
Because you're casting the spells during the resolution of Mnemonic Deluge, ignore any timing restrictions based on card type. In other words, you can cast copies of a sorcery card this way.
No other card is named in this ruling.
#3November 10, 2020· Wizards of the Coast
If you cast a spell "without paying its mana cost," you can't choose to cast it for any alternative costs. You can, however, pay additional costs. If the card has any mandatory additional costs, you must pay those to cast it.
No other card is named in this ruling.
#4November 10, 2020· Wizards of the Coast
If the card you copy has in its mana cost, you must choose 0 as the value of X when casting the copy without paying its mana cost.
No other card is named in this ruling.