That says the DM might call for a Charisma (Intimidation) check when when [a character or monster attempts] to influence someone through overt threats, hostile actions, and physical violence. This leaves room for the possibility that the DM might not call for for a Charisma (Intimidation) check when when [a character or monster attempts] to influence someone through overt threats, hostile actions, and physical violence. An example of when a DM woukd not call for a Charidma (Intimidation) check is when the character or monster’s attempt to influence someone through overt threats, hostile actions, and physical violence doesn’t have a possibility of failure or isn’t uncertain.