PHB píše:
Threatening Reach: Some creatures have an ability
called threatening reach. This lets them make opportunity
attacks against nonadjacent enemies. If an enemy
leaves a square that’s within the creature’s reach, or if
an enemy anywhere within the creature’s reach makes
a ranged attack or an area attack, the creature can
make an opportunity attack against that enemy.
Tak jsem si to vyhledal a podle vyse pospaneho by to mohla byt treba jeste zona ohrozeni/hrozby nebo neco v tom duchu.