Mana value
The mana value of an object is a number that determines the total amount of mana in its mana cost.
History
"Mana value" was originally known as "casting cost" or "total casting cost" prior to Sixth Edition. With the Sixth Edition rules changes, "casting cost" became "converted mana cost" (or "CMC" for short). The term "mana value" was introduced in Strixhaven: School of Mages.[1][2] Thereafter, all cards prior to this set, have their oracle text updated to reflect this change.[3]
Rules
From the Comprehensive Rules (June 7, 2024—Modern Horizons 3)
- 202.3. The mana value of an object is a number equal to the total amount of mana in its mana cost, regardless of color.
Example: A mana cost of {3}{U}{U} translates to a mana value of 5.
- 202.3a The mana value of an object with no mana cost is 0, unless that object is the back face of a transforming double-faced permanent or is a melded permanent.
- 202.3b The mana value of a transforming double-faced permanent or spell’s back face is calculated as though it had the mana cost of its front face. If a permanent or spell is a copy of the back face of a transforming double-faced card (even if the card representing that copy is itself a double-faced card), the mana value of the copy is 0.
Example: Huntmaster of the Fells is a transforming double-faced card with mana cost {2}{R}{G}. Its mana value is 4. After it transforms to its other face (Ravager of the Fells), its mana value remains 4.
Example: A Clone enters the battlefield as a copy of Ravager of the Fells. Its mana value is 0.
Example: Insectile Aberration is the back face of a transforming double-faced card whose front face has mana cost {U}. It becomes a copy of Ravager of the Fells. Its mana value becomes 0.
- 202.3c The mana value of a melded permanent is calculated as though it had the combined mana cost of the front faces of each card that represents it. If a permanent is a copy of a melded permanent (even if that copy is represented by two other meld cards), the mana value of the copy is 0.
- 202.3d The mana value of a split card not on the stack or of a fused split spell on the stack is determined from the combined mana costs of its halves. Otherwise, while a split card is on the stack, the mana value of the spell is determined by the mana cost of the half that was chosen to be cast. See rule 709, “Split Cards.”
- 202.3e When calculating the mana value of an object with an {X} in its mana cost, X is treated as 0 while the object is not on the stack, and X is treated as the number chosen for it while the object is on the stack.
- 202.3f When calculating the mana value of an object with a hybrid mana symbol in its mana cost, use the largest component of each hybrid symbol.
Example: The mana value of a card with mana cost {1}{W/U}{W/U} is 3.
Example: The mana value of a card with mana cost {2/B}{2/B}{2/B} is 6.
- 202.3g Each Phyrexian mana symbol in a card’s mana cost contributes 1 to its mana value.
Example: The mana value of a card with mana cost {1}{W/P}{W/P} is 3.
From the glossary of the Comprehensive Rules (June 7, 2024—Modern Horizons 3)
- Mana Value
- The total amount of mana in a mana cost, regardless of color. See rule 202.3.
The mana value of an object is an integer and is always greater than or equal to zero. Mana value is determined by converting the symbols of the card or spell's mana cost into numbers and calculating the sum of those numbers. Mana symbols represented by a number, including monocolored hybrid mana symbols (
), are converted into that number. All other mana symbols are converted into 1. Cards without a mana cost, such as lands, have a mana value of 0.
The mana value of a spell or permanent may vary if the card has 
in the mana cost or if the card has multiple sets of characteristics the player can choose from when playing the card (split cards, adventurer cards, and modal double-faced cards (MDFCs)). When an object with X in the mana cost is on the stack, X equals whatever value was chosen for it when it was put on the stack. In any other zone, X equals 0. When a card with multiple sets of characteristics is on the stack or battlefield, its mana value is determined by the characteristics of the side that was played. When a split card is in any other zone, the mana value is determined by adding both mana costs together. When an adventurer card is in any other zone, its mana value is determined by the creature's mana cost. When a MDFC is in any zone, its mana value is determined by the front face.
Examples:
- Spells with mana costs of
and 
each have a mana value of 1. - Spells with mana costs of
and each have a mana value of 3. - Spells with mana costs of
and 
each have a mana value of 5.
Odd or even mana cost
Some cards care about if the mana value is odd or even.
- Ashling's Prerogative (Lorwyn)*
- Void Winnower (Battle for Zendikar)*
- Extinction Event (Ikoria: Lair of Behemoths)*
- Gyruda, Doom of Depths (Ikoria: Lair of Behemoths)
- Lavabrink Venturer (Ikoria: Lair of Behemoths)*
- Obosh, the Preypiercer (Ikoria: Lair of Behemoths)
^* Features the reminder text: zero is even.
Cost matters
- Scryfall search: oracle:"mana value"
"Cost matters" was a theme in Scourge that encouraged players to use spells with high mana values. In addition to providing numerous creatures and other spells with mana values 6 or greater, several cards were printed that enhanced or facilitated them. This theme returned as the green-blue mechanic in Commander Legends and as the Prismari mechanic in Strixhaven: School of Mages.
References
- ↑ Blake Rasmussen (February 18, 2021). "The First Lesson: Introduction to Strixhaven". magicthegathering.com. Wizards of the Coast.
- ↑ Magic Esports (February 18, 2021). "A small update in MTGStrixhaven". Twitter.
- ↑ Jess Dunks and Matt Tabak (April 16, 2021). "Strixhaven: School of Mages and Commander (2021 Edition) Release Notes". magicthegathering.com. Wizards of the Coast.
Obsolete terminology
From the glossary of the Comprehensive Rules (June 7, 2024—Modern Horizons 3)
- Converted Mana Cost (Obsolete)
- An obsolete term for mana value. Cards printed with this term have received errata in the Oracle card reference.