Needlebite Trap

Name: Needlebite Trap
Brand: Magic: The Gathering
Price: 0.22 USD

If an opponent gained life this turn, you may pay {B} rather than pay this spell's mana cost.
Target player loses 5 life and you gain 5 life.

Needlebite Trap has 1 printing, first in Zendikar (2009). EDHREC ranks it #23,058 among Commander cards. It has 4 official rulings.

Legality

Cards that show up in the same decks on EDHREC.

2009-10-01: You may ignore a Trap's alternative cost condition and simply cast it for its normal mana cost. This is true even if its alternative cost condition has been met.
2009-10-01: Needlebite Trap's alternative cost condition checks only whether life was gained. It doesn't care whether life was also lost. For example, if an opponent gained 4 life and lost 6 life during the turn, that player will have a lower life total than they started the turn with — but you can still cast Needlebite Trap by paying {B}.
2009-10-01: Casting a Trap by paying its alternative cost doesn't change its mana cost or mana value. The only difference is the cost you actually pay.
2009-10-01: Effects that increase or reduce the cost to cast a Trap will apply to whichever cost you chose to pay.