Which of the following resources are shared among teammates in a Two-Headed Giant game?

In a Two-Headed Giant game, teammates share key resources that affect gameplay dynamics. Specifically, one of the primary shared aspects is the life total and poison counters. Each team collectively manages a single life total, which means that the team must strategize together regarding how to allocate their resources to avoid losing that combined life total. In this format, both players are considered a single entity for the purposes of life and poison counters, which influences their decision-making and tactical play.

While other resources like cards in hand and mana resources are often managed individually within the context of the game, teammates do not share those components directly. Each player in a Two-Headed Giant still has their own hand of cards and their own mana pool, which they can utilize independently. Consequently, although teamwork is critical in strategizing with these individual resources, they are not 'shared' in the same sense that life totals and poison counters are.

This nuanced understanding of resource sharing in Two-Headed Giant is essential for effectively managing gameplay strategies, leading to the conclusion that life total and poison counters are indeed the shared resources among the teammates.