Affinity

From MTG Salvation Wiki

Affinity is a keyword ability that reduces the mana cost of a spell by the number of permanents of a certain type that player controls. The ability is always written as "Affinity for" something. The most common instance is "Affinity for artifacts" (see Frogmite); however, a cycle of Golems (consisting of Dross Golem, Oxidda Golem, Razor Golem, Spire Golem, and Tangle Golem) has appeared in the Darksteel expansion, with each of the artifact creatures with affinity for a particular basic land type.

All tournament-legal cards with affinity were printed during the Mirrodin block.

From the Comprehensive Rules: 502.31. Affinity 502.31a Affinity is a static ability that functions while the spell is on the stack. “Affinity for [text]" means “This spell costs you less to play for each [text] you control." 502.31b The affinity ability reduces only generic mana costs; it doesn't reduce how much colored mana you have to pay for a spell. Affinity can't reduce the cost to play a spell to less than 0. 502.31c If a spell has multiple instances of affinity, each of them applies.

[edit] Rulings

• The affinity ability reduces only the amount of generic mana you pay. It can't reduce how much colored mana you pay.
• Affinity can't reduce the cost to play a spell to less than .
• Affinity doesn't change the spell's mana cost or converted mana cost. It just changes how much mana you pay to play the spell.
• The cost reduction is set before you have to pay any costs for the spell. If you sacrifice an artifact while paying the spell's costs, that artifact still counts toward the cost reduction.

[edit] Color percentages

[edit] Notable cards with affinity

Frogmite, Myr Enforcer, Thoughtcast - used in affinity decks