Mana and Costs
This document provides an overview of the rules for mana and costs in Magic: The Gathering. For implementation details in Rummage, see the relevant code in the mana.rs file.
Mana Types
Magic: The Gathering has six types of mana:
- White (W)
- Blue (U)
- Black (B)
- Red (R)
- Green (G)
- Colorless (C)
Additionally, there is the concept of generic mana, represented by numbers (e.g., {1}, {2}), which can be paid with any type of mana.
Mana Costs
A spell's mana cost appears in the upper right corner of the card and consists of mana symbols. For example:
- {2}{U} means "two generic mana and one blue mana"
- {W}{W} means "two white mana"
- {X}{R}{R} means "X generic mana and two red mana" where X is chosen by the player
Mana Pool
Players have a mana pool where mana is stored until spent or until a phase or step ends. Mana in a player's mana pool can be spent to pay costs or may be lost when a phase or step ends.
Mana Sources
Mana is produced by mana abilities, which come from various sources:
- Land abilities: Basic lands and many nonbasic lands
- Creature abilities: Mana dorks and other creatures
- Artifact abilities: Mana rocks and other artifacts
- Enchantment abilities: Various enchantments
- Spells: Some instants and sorceries produce mana
Additional Costs
Many spells and abilities have additional costs beyond their mana cost:
- Tap costs: {T} means "tap this permanent"
- Life costs: "Pay N life"
- Sacrifice costs: "Sacrifice a creature"
- Discard costs: "Discard a card"
- Exile costs: "Exile a card from your graveyard"
Alternative Costs
Some spells can be cast for alternative costs:
- Flashback: Cast from graveyard for a different cost
- Overload: Cast with a different effect for a different cost
- Foretell: Cast from exile for a different cost
- Evoke: Cast with a sacrifice trigger for a reduced cost
Cost Reduction
Various effects can reduce costs:
- "Spells you cast cost {1} less to cast"
- "This spell costs {1} less to cast for each artifact you control"
- "The first creature spell you cast each turn costs {2} less to cast"
Cost Increases
Similarly, effects can increase costs:
- "Spells your opponents cast cost {1} more to cast"
- "Activated abilities cost {2} more to activate"
- "Creature spells with flying cost {1} more to cast"
Special Mana Types
Beyond the basic types, there are special types of mana:
- Snow mana ({S}): Produced by snow permanents
- Phyrexian mana ({W/P}, {U/P}, etc.): Can be paid with either colored mana or 2 life
- Hybrid mana ({W/U}, {B/R}, etc.): Can be paid with either of two colors
- Colorless-specific mana ({C}): Must be paid with colorless mana, not any color
Mana Conversion
Mana conversion for costs follows these rules:
- Colored mana requirements must be paid with the exact color
- Generic mana can be paid with any type of mana
- Colorless-specific requirements must be paid with colorless mana
- Special mana symbols follow their own rules
Related Documentation
For more information on how mana and costs are implemented in Rummage, see:
- Casting Spells: How mana is used to cast spells
- Abilities: How mana abilities work
- Stack: How mana abilities bypass the stack