Ghalta the Unstoppable — ruling 1

Ghalta the Unstoppable's cost reduction ability can't reduce the total cost to cast the spell below {G}.

Ghalta the Unstoppable — ruling 2

Once you determine the cost to cast Ghalta the Unstoppable, you may activate mana abilities to pay that cost. If the greatest power of creatures you control changes while activating mana abilities, the cost to cast Ghalta remains what you previously determined.

Ghalta the Unstoppable — ruling 3

Ghalta the Unstoppable's mana value doesn't change no matter what the greatest power of creatures you control is.

Ghalta the Unstoppable — ruling 4

Once you announce you're casting a spell, no player may take actions until the spell has been paid for. Notably, opponents can't try to reduce the power of creatures you control.

Ghalta the Unstoppable — ruling 5

The first step of casting a spell is to move it to the stack. If this causes the greatest power of creatures you control to change (perhaps because you control a creature whose power is determined by the number of cards in your hand), that new power will be used to determine the cost reduction.

Ghalta the Unstoppable : règles, fonctionnement et interactions (MTG)

Ghalta the Unstoppable 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 costs less to cast, where X is the greatest power among creatures you control. Trample Other creatures you control have trample.

How it works : Ghalta the Unstoppable

Original English text — Wizards of the Coast / Scryfall

#1August 21, 2026· Wizards of the Coast
Ghalta the Unstoppable's cost reduction ability can't reduce the total cost to cast the spell below .
No other card is named in this ruling.
#2August 21, 2026· Wizards of the Coast
Once you determine the cost to cast Ghalta the Unstoppable, you may activate mana abilities to pay that cost. If the greatest power of creatures you control changes while activating mana abilities, the cost to cast Ghalta remains what you previously determined.
No other card is named in this ruling.
#3August 21, 2026· Wizards of the Coast
Ghalta the Unstoppable's mana value doesn't change no matter what the greatest power of creatures you control is.
No other card is named in this ruling.
#4August 21, 2026· Wizards of the Coast
Once you announce you're casting a spell, no player may take actions until the spell has been paid for. Notably, opponents can't try to reduce the power of creatures you control.
No other card is named in this ruling.
#5August 21, 2026· Wizards of the Coast
The first step of casting a spell is to move it to the stack. If this causes the greatest power of creatures you control to change (perhaps because you control a creature whose power is determined by the number of cards in your hand), that new power will be used to determine the cost reduction.
No other card is named in this ruling.