@JeremyECrawford rider on controlled mount wants to attack mid-move. Do rider and mount share one turn, or does rider need to Ready attack?
— Armando Doval (@armando_doval) April 26, 2017
A rider and a controlled mount have separate turns, but they have the same initiative, which means you decide which one goes first. #DnD https://t.co/7zuWYwEFUu
— Jeremy Crawford (@JeremyECrawford) April 26, 2017
@armando_dovalIf the controlled mount had higher initiative, it gets a second turn the round it’s mounted. Does it get to use all of its movement again? Yes.
— Jeremy Crawford (@JeremyECrawford) April 26, 2017
@JeremyECrawford Can you choose on each round or do you have to use the same order every round?
— Armando Doval (@armando_doval) April 26, 2017
The initiative rules assume that ties are sorted out when a tie first occurs. But a DM might allow the choice to occur each round. #DnD https://t.co/vqyxMP6coH
— Jeremy Crawford (@JeremyECrawford) April 26, 2017
@armando_doval Sure thing!
— Jeremy Crawford (@JeremyECrawford) April 26, 2017
@JeremyECrawford I listen your podcast Dragon Talk: seems like you said that you and the controlled mount have the same turn. Does this mean that the rider and mount share a single turn?
But this tweet seems contradict the podcast! Which is true my master?— Draconis (@DerynDraconis) March 4, 2018
A controlled mount has its own turn, but that turn takes place on the same initiative count as the rider’s turn. #DnD https://t.co/bVTFaOxL6V
— Jeremy Crawford (@JeremyECrawford) March 4, 2018
I think the most important follow up question is: if you choose for it to be independent, does the DM seize control temporarily? Otherwise, what does "independent mount" mean in terms of Find Steed.
— Bardface (@brightwoodbard) March 13, 2018
If your character's mount acts independently, the DM decides whether you control the mount or the DM does. The main things about an independent mount are that (a) it gets a full turn on its own initiative and (b) it might act unexpectedly. #DnD https://t.co/320Ywkso0u
— Jeremy Crawford (@JeremyECrawford) March 14, 2018
The core question was never explicitly answered. When a mount is moving, can the rider swing at an enemy while the mount is moving?
No, because it is the mount’s turn, not the players’,.
Because it’s separate turn for both, the rider can always use ready action, then trigger the attack when the mount is passing by the enemy.
Yes. The rules say the mount moves and acts even on the turn you mount it. You mount it on your turn, so it must be able to move and act on your turn. The mount having a separate turn does not mean it can only act and move on that turn. You do not need to ready an action to do this, because your mount and you can act as an unit.