In episode e1, Island Assault pt. 3, we messed up the rules on spell casting!
Typically we don't care about messing up rules, but you know that by now ;). In this case we made Derek (Jayce) succumb to peer pressure when he cast misty step to get closer to the Kulmaata. He teleported 30-feet to be right next to her and we convinced him that he couldn't attack because he'd already cast a spell. Wrong. Misty Step is a bonus action. That means he 100% could have cast a misty step, teleported next to the Kulmaata and then laid a walloping of Sea-Bitch Justice on her. Maybe if he'd gotten in that extra hit the lady-rak would have gone down one round earlier and he never would have been knocked out.
Don't forget to read your casting time, kids! Your PC's life might depend on it.