From Descent-Community Wiki 1.1
Play this card when a hero enters an empty space. He tests . If he fails, he suffers 1 and loses 1 movement point. If he has no movement points to lose (such as if he suffered fatigue to move), he is Stunned.
|Q: Can a hero suffer fatigue to gain a movement point in response to a "Pit Trap" in order to avoid being Stunned?|
|A: No, the effects of "Pit Trap" are applied immediately|
|Source FAQ v1.6 page 4|