Magic: The Gathering Comprehensive Rules Changes - Planar Chaos to Future Sight

Old rule (Planar Chaos)	New rule (Future Sight)
502.31b. [Click to view all changes.]
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.	502.31b. The affinity ability reduces only generic mana costs; it doesn't reduce how much colored mana you have to pay for a spell.

Old rule (Planar Chaos)

New rule (Future Sight)

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.

502.31b.

The affinity ability reduces only generic mana costs; it doesn't reduce how much colored mana you have to pay for a spell.