Both at 0: It's a Draw
Judge Level 1Flame Rift takes both players to 0 at once — who wins?
Cards involved
All or nothing
You are at 4 life, your opponent at 3. You cast Flame Rift: 4 damage to each player — including you.
What happens?
Flame Rift resolves.
You drop to 0, your opponent to -1. Who wins?
Pick an answer to continue.
State-based actions check both life totals at the same time: both are at 0 or less, both lose in the same moment — the game is a draw (104.4b). "Deeper in the negative" has no rules meaning.
104.4bIf a game that’s not using the limited range of influence option (including a two-player game) somehow enters a “loop” of mandatory actions, repeating a sequence of events with no way to stop, the game is a draw. Loops that contain an optional action don’t result in a draw.
A draw
No winner. Do the math before casting something like this — at 5 life you would have won.
104.4bIf a game that’s not using the limited range of influence option (including a two-player game) somehow enters a “loop” of mandatory actions, repeating a sequence of events with no way to stop, the game is a draw. Loops that contain an optional action don’t result in a draw.
The lifelink classic
Same logic in combat: if two players with lifelink creatures knock each other to 0 simultaneously, that's a draw too — combat damage and life gain happen at the same time (510.2), checks come afterwards.
510.2Second, all combat damage that’s been assigned is dealt simultaneously. This turn-based action doesn’t use the stack. No player has the chance to cast spells or activate abilities between the time combat damage is assigned and the time it’s dealt.
Stack
Flame Rift
4 damage to EACH player
The stack is empty.