how much life do you have to gain to win in magic the gathering?

[Batassassin]

how much life do i need to gain to win a game of mtg? is it 40 or 100 life?

[Arix]

That depends on whether you control Felidar Sovereign or Test of Endurance.

If you have neither, then you need infinity trillion and six. Squared.

[Kenji]

In case Arix's tongue-in-cheek answer wasn't tongue in...cheeky enough for ya:

Without a card that tells you that you'll win the game for having a certain amount of life, no amount of life gain causes you to win the game.

[Mountain]

That depends on whether you control Felidar Sovereign or Test of Endurance.

If both of these are on the battlefield at the same time, do you need 40 or 50 to win?

[Arix]

40. Test doesn't replace Felidar, it counts alongside it.

[DatAsh]

If you have two conditional win conditions, either will happen when able.