Here's a very silly situation that I'm sure would be easy to rule around, but as an exercise to understand the rules better, I'd still like to know how this works. It might even just be a variation of Can you move on your turn, and then use the Ready Action to move again on another creature's turn? (c.f. also the linked What are the basic limitations for using a Reaction to move? Does movement used on your Turn matter? for context)
Here are the steps I'm checking are possible:
- Round zero
- You are mounted on a controlled mount, and you share initiative.
- You chose that the horse acts first (as per Jeremy Crawford's tweet)
- As your action for the turn, you ready an action to dismount the horse when it finishes moving.
- Round one
- On the horses first turn in round one, you direct it to use the dash action (granting it an amount of extra movement, equal to its base speed) and then to move a distance equal to double its base speed
- \$distance_{total} = movement_{base} + movement_{dash} = 2 \times speed_{mount}\$.
- After the mount's movement is over your readied action triggers and you dismount
- On your turn in round one, you take bonus actions/free interactions (basically, anything but an action) and no more than half your movement and remain within 5ft of the mount
- You use the remaining half of your movement to mount the horse for the first time this turn.
- When you mount it, you chose the mount to go after you in initiative order this time, and ready an action to dismount the horse as it finishes moving on it's next turn.
- Mount round 1, turn 2 (😨), you direct it take the dash action, (granting it an amount of extra movement, equal to its speed) and move its speed again.
- \$distance_{total} = movement_{base} + 2\times movement_{dash} = 3 \times speed_{mount}\$.
- Other creatures get to act
- Round two
- On your next turn, you mount the horse and choose for it to come before you in initiative, thus acting before you in round 3.
- Ready an action (as in turn 0) to dismount when the mount finishes moving in round 3.
- Repeat the actions and movements taken in round 1.
- (Optionally, if you interpret 'A controlled mount can move and act even on the turn that you mount it.' to mean the horse gets to 'move and act' on the same turn (i.e. your turn 1, round 2) then it gets to move again before round 3 comes around. This is not the standard interpretation.
In essence, if I do the above (or similar, accounting for any mistakes I've made in the explanation) can I double dip on my mounts extra movement by changing when in initiative order it goes, essentially granting it second turn and use of dash? It would be limited to only moving it's speed in a single round:
Every character and monster has a speed, which is the distance in feet that the character or monster can walk in 1 round.
However the Dash action grants extra movement (n.b., to be watertight, the quoted passage would have to say 'current round' not 'current turn', but the two words are used inconsistently, and the same interpretation would prevent dash ever granting extra movement for a round.)
When you take the Dash action, you gain extra movement for the current turn. The increase equals your speed, after applying any modifiers.
By the way, this isn't Does The Amazing Lightspeed Horse work, RAW? as I'm using readied actions to mount and dismount, but a similar question could be asked combining the two techniques.
Is this possible?