Graveyard Shift — ruling 1

The game checks whether it is legal to cast a spell before costs are determined or mana abilities are activated while casting it. If cards are removed from your graveyard after that point, such as by exiling Jack-o'-Lantern from your graveyard to pay for its mana ability, this won't affect whether you can legally cast Graveyard Shift, even if that reduces the number of mana values in your graveyard to below five.

Graveyard Shift — ruling 2

If an effect allows you to cast Graveyard Shift from your graveyard, you may cast it any time you could cast an instant if you have five or more mana values among cards in your graveyard immediately before you begin to cast it, even if moving it to the stack would reduce that number to four.

Graveyard Shift — ruling 3

“Five or more mana values among cards in your graveyard” means there are at least five mana values among those cards.

Graveyard Shift — ruling 4

The mana value of a split card in the graveyard is the total mana value of both halves of that card. It does not have two mana values.

Graveyard Shift — ruling 5

The mana value of a double-faced card in your graveyard is always the mana value of the front face.

Graveyard Shift — ruling 6

X is 0 when determining the mana value of a card in your graveyard.

Graveyard Shift — ruling 7

The mana value of a land card is 0.

Graveyard Shift : règles, fonctionnement et interactions (MTG)

Graveyard Shift 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

This spell has flash as long as there are five or more mana values among cards in your graveyard. Return target creature card from your graveyard to the battlefield.

How it works : Graveyard Shift

Original English text — Wizards of the Coast / Scryfall

#1April 29, 2022· Wizards of the Coast
The game checks whether it is legal to cast a spell before costs are determined or mana abilities are activated while casting it. If cards are removed from your graveyard after that point, such as by exiling Jack-o'-Lantern from your graveyard to pay for its mana ability, this won't affect whether you can legally cast Graveyard Shift, even if that reduces the number of mana values in your graveyard to below five.
No other card is named in this ruling.
#2April 29, 2022· Wizards of the Coast
If an effect allows you to cast Graveyard Shift from your graveyard, you may cast it any time you could cast an instant if you have five or more mana values among cards in your graveyard immediately before you begin to cast it, even if moving it to the stack would reduce that number to four.
No other card is named in this ruling.
#3April 29, 2022· Wizards of the Coast
“Five or more mana values among cards in your graveyard” means there are at least five mana values among those cards.
No other card is named in this ruling.
#4April 29, 2022· Wizards of the Coast
The mana value of a split card in the graveyard is the total mana value of both halves of that card. It does not have two mana values.
No other card is named in this ruling.
#5April 29, 2022· Wizards of the Coast
The mana value of a double-faced card in your graveyard is always the mana value of the front face.
No other card is named in this ruling.
#6April 29, 2022· Wizards of the Coast
X is 0 when determining the mana value of a card in your graveyard.
No other card is named in this ruling.
#7April 29, 2022· Wizards of the Coast
The mana value of a land card is 0.
No other card is named in this ruling.