Ghalta, Primal Hunger — ruling 1

To determine Ghalta's total cost, start with the mana cost (or an alternative cost if another card's effect allows you to pay one instead), add any cost increases, then apply any cost reductions. Ghalta's mana value remains unchanged, no matter what the total cost to cast it was.

Ghalta, Primal Hunger — ruling 2

The total cost to cast Ghalta is locked in before you pay that cost. For example, if you control three 2/2 creatures, including one you can sacrifice to add {C}, the total cost of Ghalta is {4}{G}{G}. Then you can sacrifice the creature when you activate mana abilities just before paying the cost.

Ghalta, Primal Hunger — ruling 3

If a creature's power is somehow less than 0, it subtracts from the total power of your other creatures. If the total power of your creatures is 0 or less, Ghalta's cost remains {10}{G}{G}.

Ghalta, Primal Hunger — ruling 4

Ghalta's first ability can't reduce its cost below {G}{G}.

Ghalta, Primal Hunger : règles, fonctionnement et interactions (MTG)

Ghalta, Primal Hunger 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 total power of creatures you control. Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Complete guide

Ghalta, Primal Hunger is a massive Elder Dinosaur that rewards you for maintaining a powerful board state. Despite its daunting mana cost of twelve, its unique reduction ability allows you to deploy this 12/12 threat for as little as two green mana. Understanding how to calculate its cost is key to stomping over your opponents.

Calculating the Primal Discount

Ghalta's first ability reduces its cost by {X}, where X is the total power of creatures you control. To determine the final price, start with the mana cost of {10}{G}{G}, add any external cost increases, then subtract the total power of your creatures. Note that this ability only reduces the generic portion of the cost; you will always have to pay at least {G}{G} to cast Ghalta, Primal Hunger.

The Importance of Mana Value

Even if you pay only two mana to cast Ghalta, its mana value (formerly known as converted mana cost) remains 12. This is based solely on the symbols printed in the upper right corner of the card. This high mana value can be beneficial for cards that check for the highest mana value among permanents you control, regardless of how much mana was actually spent to cast it.

Locking in the Cost

The game determines the total cost of Ghalta before you actually pay for it. This is crucial for creatures with mana abilities. If you control a creature you can sacrifice for mana, its power contributes to the discount before you sacrifice it to pay for the remaining cost. Conversely, if a creature has negative power due to a debuff, it will reduce your total power total, potentially making Ghalta more expensive.

Combat and Trample

As a 12/12 with Trample, Ghalta is designed to end games. Trample allows Ghalta to deal lethal damage to blockers and carry the remaining excess damage over to the defending player or planeswalker. Because Ghalta's power is so high, very few creatures can effectively block it without the player taking significant damage.

Interaction examples

A Colossal Discount

Blightsteel Colossus

If you control Blightsteel Colossus, its power is 11. When you go to cast Ghalta, Primal Hunger, the game checks your total power. Since 11 power is greater than the {10} generic mana in Ghalta's cost, the generic cost is reduced to zero. You only need to pay {G}{G} to cast Ghalta.

Eldrazi Assistance

Ulamog, the Infinite Gyre

With Ulamog, the Infinite Gyre on the battlefield, you have 10 power. The cost reduction exactly covers the {10} generic mana in Ghalta's mana cost. Step by step: you announce Ghalta, the cost is calculated as {10}{G}{G} minus 10 power, resulting in a total cost of {G}{G}. You pay the two green mana, and Ghalta is successfully cast.

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

How it works : Ghalta, Primal Hunger

Original English text — Wizards of the Coast / Scryfall

#1January 19, 2018· Wizards of the Coast
To determine Ghalta's total cost, start with the mana cost (or an alternative cost if another card's effect allows you to pay one instead), add any cost increases, then apply any cost reductions. Ghalta's mana value remains unchanged, no matter what the total cost to cast it was.
No other card is named in this ruling.
#2January 19, 2018· Wizards of the Coast
The total cost to cast Ghalta is locked in before you pay that cost. For example, if you control three 2/2 creatures, including one you can sacrifice to add , the total cost of Ghalta is . Then you can sacrifice the creature when you activate mana abilities just before paying the cost.
No other card is named in this ruling.
#3January 19, 2018· Wizards of the Coast
If a creature's power is somehow less than 0, it subtracts from the total power of your other creatures. If the total power of your creatures is 0 or less, Ghalta's cost remains .
No other card is named in this ruling.
#4January 19, 2018· Wizards of the Coast
Ghalta's first ability can't reduce its cost below .
No other card is named in this ruling.