In a two-headed giant game, does a player losing life affect both players' shared life total?

In Two-Headed Giant (2HG), each team has a single shared life total, which starts at 30 life (CR 810.6). Individual players do not have separate life totals — the team's life total is the only one that matters.

When a player on a team loses life, that loss is applied directly to the team's shared life total (CR 810.8). It doesn't matter which player on the team is the target of the life loss effect; the result is the same reduction to the shared pool. Similarly, when a player gains life, the team's shared total goes up (CR 810.8).

The team loses the game when their shared life total reaches 0 or less, or when it is 0 or less as a state-based action is checked (CR 810.7). Both players on the team lose simultaneously under this condition.

Concrete example: Your opponent targets you specifically with a Lightning Bolt dealing 3 damage, causing you to lose 3 life. Even though only you were targeted, your team's shared life total drops from 30 to 27. Your teammate's 'personal' life is unaffected because there is no personal life — only the shared total exists.

Note that some effects reference an individual player losing life for triggered ability purposes (e.g., 'whenever you lose life'). In 2HG, such triggers still function on a per-player basis even though the life loss comes from the shared total (CR 810.8).