Courageous Resolve

If you cast Courageous Resolve in a Two-Headed Giant game and your team's life total is 5 or less when it resolves, your team can't lose the game that turn and the opposing team can't win the game that turn.

If an effect would cause you to exchange life totals with another player whose life total is lower than yours, the exchange won't happen. Neither player's life total changes.

Courageous Resolve checks your life total only at the time it resolves. If it's 5 or less at that time, even if you gain life later in the turn, you'll still be unable to lose life or lose the game that turn, and your opponents will still be unable to win the game that turn.

Spells and abilities that would normally cause you to lose life still resolve, but the life-loss part simply has no effect.

You can't pay a cost that includes the payment of any amount of life other than 0 life. However, you can choose to be dealt damage, even though that damage won't result in your life total changing.

Courageous Resolve doesn't prevent damage. Rather, it changes the results of that damage. For example, if a creature with lifelink deals damage to you, you won't lose any life, but its controller will still gain that much life. Similarly, if a creature with infect deals damage to you, you'll still receive that many poison counters.