## Yes you can. ## The Ready action is what you're looking for. It's explained on p.192 of the player's handbook. > First, you decide what perceivable circumstance will trigger your reaction. For you this would be, "If anything nasty comes towards me" > Then, you choose the action you will take in response to that trigger, **or you choose to move up to your speed in response to it.** So your response would be, "I run in the opposite direction!" So you use your action Ready to run and then, when a monster approaches you, you may use your reaction to move away. Generally you won't also be able to also Dash since that would require another action.