Magus of the Mind — ruling 1

If you cast a card “without paying its mana cost,” you can’t pay any alternative costs. You can, however, pay additional costs. If the card has any mandatory additional costs, such as that of Tormenting Voice, those must be paid to cast the card.

Magus of the Mind — ruling 2

If no spells have been cast in the turn you activate Magus of the Mind’s ability, X is one.

Magus of the Mind — ruling 3

You may play a land exiled this way only if you have an available land play this turn.

Magus of the Mind — ruling 4

You must follow the normal timing permissions and restrictions for cards you cast this way.

Magus of the Mind — ruling 5

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

Magus of the Mind — ruling 6

Any of the cards you don’t play will remain in exile.

Magus of the Mind : règles, fonctionnement et interactions (MTG)

Magus of the Mind 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

, , Sacrifice this creature: Shuffle your library, then exile the top X cards, where X is one plus the number of spells cast this turn. Until end of turn, you may play lands and cast spells from among cards exiled this way without paying their mana costs.

How it works : Magus of the Mind

Original English text — Wizards of the Coast / Scryfall

#1August 25, 2017· Wizards of the Coast
If you cast a card “without paying its mana cost,” you can’t pay any alternative costs. You can, however, pay additional costs. If the card has any mandatory additional costs, such as that of Tormenting Voice, those must be paid to cast the card.
No other card is named in this ruling.
#2August 25, 2017· Wizards of the Coast
If no spells have been cast in the turn you activate Magus of the Mind’s ability, X is one.
No other card is named in this ruling.
#3August 25, 2017· Wizards of the Coast
You may play a land exiled this way only if you have an available land play this turn.
No other card is named in this ruling.
#4August 25, 2017· Wizards of the Coast
You must follow the normal timing permissions and restrictions for cards you cast this way.
No other card is named in this ruling.
#5August 25, 2017· Wizards of the Coast
If the card has in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
No other card is named in this ruling.
#6August 25, 2017· Wizards of the Coast
Any of the cards you don’t play will remain in exile.
No other card is named in this ruling.