8th Edition

: Add  to your mana pool. If you control an Urza's Power-Plant and an Urza's Tower, add  to your mana pool instead.

: Add  to your mana pool. If you control an Urza's Mine and an Urza's Tower, add  to your mana pool instead.

: Add  to your mana pool. If you control an Urza's Mine and an Urza's Power-Plant, add  to your mana pool instead.

Casting Cost: 

Whenever a Forest is tapped for mana, its controller adds  to his or her mana pool (in addition to the mana the land produces).

Casting Cost:

If you control a creature, damage that would reduce your life total to less than 1 reduces it to 1 instead.