Core rule · Rules Tome 2.0.8 § 508.6.1
Death React
A dying Character may perform this React before it leaves play.
How it works
Full rule
Death React is shorthand for “React: Before this character is killed.” It occurs after the Character is determined to be dying and before it is placed in the discard pile.
At the table
Example
A Character reduced to its HP threshold may use its printed Death React before being discarded.
Watch for this
Common mistake
A Character gets one death determination and window, not another one for each additional wound suffered while already dying.