The active character is the player whose turn it currently is.

During the encounter phase the responsible character is the active character.

During setup the responsible character is the active character (as soon as determined).

Clarifications:

• When the character phase begins the players must immediately decide who becomes the active character.
• A player stays the active character until they pass their turn. When they end their turn they have to decide who becomes the next active character. (Unless all characters have already played their turn. Then, the character phase ends and the encounter phase begins.)
• You remain the active character, while another character draws encounter cards, performs actions, or resolves effects during your turn.