Nahiri, Forged in Fury — ruling 1

An "equipped creature you control" is any creature you control with one or more Equipment attached to it.

Nahiri, Forged in Fury — ruling 2

Nahiri's last ability will trigger once for each equipped creature you control that attacks, no matter how many Equipment are attached to any of them.

Nahiri, Forged in Fury — ruling 3

You may play the card exiled with Nahiri's ability even if Nahiri or the equipped creature leaves the battlefield or you lose control of them.

Nahiri, Forged in Fury — ruling 4

Playing the exiled card follows the normal rules for playing that card. Unless you're casting an Equipment spell this way, you must pay the spell's costs, and you must follow all applicable timing rules. For example, if the card is a creature card, you can cast that card by paying its mana cost only during your main phase while the stack is empty.

Nahiri, Forged in Fury — ruling 5

If you cast an Equipment spell this way, you may choose to pay its mana cost if you want to.

Nahiri, Forged in Fury — ruling 6

One reason you might want to pay its mana cost is if there's an {X} in its mana cost. If you cast such a spell without paying its mana cost, you must choose 0 as the value of X. (If you pay its mana cost, you may choose the value of X as normal.)

Nahiri, Forged in Fury — ruling 7

Unless an effect allows you to play additional lands that turn, you can play a land card exiled with Nahiri only if you haven't played a land yet that turn.

Nahiri, Forged in Fury — ruling 8

If you don't play the card, it will remain exiled.

Nahiri, Forged in Fury : règles, fonctionnement et interactions (MTG)

Nahiri, Forged in Fury 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

Affinity for Equipment (This spell costs less to cast for each Equipment you control.) Whenever an equipped creature you control attacks, exile the top card of your library. You may play that card this turn. You may cast Equipment spells this way without paying their mana costs.

How it works : Nahiri, Forged in Fury

Original English text — Wizards of the Coast / Scryfall

#1May 12, 2023· Wizards of the Coast
An "equipped creature you control" is any creature you control with one or more Equipment attached to it.
No other card is named in this ruling.
#2May 12, 2023· Wizards of the Coast
Nahiri's last ability will trigger once for each equipped creature you control that attacks, no matter how many Equipment are attached to any of them.
No other card is named in this ruling.
#3May 12, 2023· Wizards of the Coast
You may play the card exiled with Nahiri's ability even if Nahiri or the equipped creature leaves the battlefield or you lose control of them.
No other card is named in this ruling.
#4May 12, 2023· Wizards of the Coast
Playing the exiled card follows the normal rules for playing that card. Unless you're casting an Equipment spell this way, you must pay the spell's costs, and you must follow all applicable timing rules. For example, if the card is a creature card, you can cast that card by paying its mana cost only during your main phase while the stack is empty.
No other card is named in this ruling.
#5May 12, 2023· Wizards of the Coast
If you cast an Equipment spell this way, you may choose to pay its mana cost if you want to.
No other card is named in this ruling.
#6May 12, 2023· Wizards of the Coast
One reason you might want to pay its mana cost is if there's an in its mana cost. If you cast such a spell without paying its mana cost, you must choose 0 as the value of X. (If you pay its mana cost, you may choose the value of X as normal.)
No other card is named in this ruling.
#7May 12, 2023· Wizards of the Coast
Unless an effect allows you to play additional lands that turn, you can play a land card exiled with Nahiri only if you haven't played a land yet that turn.
No other card is named in this ruling.
#8May 12, 2023· Wizards of the Coast
If you don't play the card, it will remain exiled.
No other card is named in this ruling.