Mialee: I'm not waiting for that bugbear to charge; I'm casting Sleep. (Rolls) 23 hit points fall unconscious.
DM: (knows what "unconscious" means) the badly wounded bugbear turns toward you, raising his morningstar! Then he lowers it, crashes hard on one knee, and falls on his face. Regdar, you were wrong about his buddy; he turns toward the trap's rope instead of attacking Mialee.
Regdar: Huh. Well, my Readied Action is the same - I'm trying to chop his head off. (Rolls) 16 attack, 12 damage.
DM: You whack him good, but "good" isn't enough to cut through his hairy hide. Use your Inspiration next time.
Regdar: I chase him toward the rope with my movement.
DM: The bugbear swings his morningstar to deter you, spins, and lunges for the rope. You easily dodge the swing, and chase after him, trying to cut him down with your sword. Mialee, this is bad for you, because the bugbear pulls on the rope, and you see the rocks above tumble toward you.
Regdar: It's my turn, right? Readied actions don't change initiative?
DM: Yep, new round, you're still first.
Regdar: Mialee won't survive that rock fall, but I might. I dive towards her, to push her out of the way if she's not too far away.
DM: Good thing for you that you have the highest initiative, and that she's only twenty feet away from the bugbear and the rope. Make a Reflex save with Disadvantage. Mialee, make your Reflex save with Advantage.