Bill Zebub
“It’s probably Matt Mercer’s fault.”
So when and where do you draw the line between things the player decides and things the dice decide? How is being scared (or not) different from deciding whether to keep fighting or running away? Or choosing which of two orcs to attack? Or whether to turn left or right in a dungeon?It's really no different than rolling dice to see if the orc sneaks up on you. Why is "Nah, I'm not scared" OK and not "Nah, I see the orc"?
For me, the dividing line is that players always (unless a rule specifically states otherwise) declare the actions of their characters.
So the DM is free, I guess, to say “you are afraid of the orc.” But since the player still gets to decide what actions to take, the DM’s statement is meaningless.
Now, maybe it was only intended to be a roleplaying cue. As in, you’re still free to take any actions and without penalty, but some narration to reinforce the idea of Scary Orc would be appreciated. If that’s all it means, though, then why roll dice? The DM can narrate Scary Orc and the player can pick up on that and run with it.
And if the fear is, “But what if the player doesn’t play along?” I have two answers:
1) Trust the player to contribute in ways they see fit
2) If they consistently do so in a way that runs you wrong, find new players.
Rules don’t fix table mid-matches