"Readying" an action is explained fairly directly in the player's handbook:
Ready
Sometimes you want to get the jump on a foe or wait for a particular circumstance before you act. To do so, you can take the Ready action on your turn, which lets you act using your reaction before the start of your next turn.
First, you decide what perceivable circumstance will trigger your reaction. 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. Examples include "If the cultist steps on the trapdoor, I’ll pull the lever that opens it," and "If the goblin steps next to me, I move away."
When the trigger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger.
When you ready a spell, you cast it as normal but hold its energy, which you release with your reaction when the trigger occurs. To be readied, a spell must have a casting time of 1 action, and holding onto the spell’s magic requires concentration (explained in chapter 10). If your concentration is broken, the spell dissipates without taking effect. For example, if you are concentrating on the web spell and ready magic missile, your web spell ends, and if you take damage before you release magic missile with your reaction, your concentration might be broken.
The question I have is, who and what is allowed to "ready" actions? Player characters, certainly, are permitted, and it seems very reasonable that NPCs, too can ready actions (the villains know that someone is robbing the fortress, and array their archers for a surprise attack when the throne room is breached). But how far can this "readied action" extend? Does it require a degree of intelligence, lending strategy and timing to their abilities? From a rules standpoint, is it necessary for a creature to have "Ready an action" among their options, along with a reaction option to "execute a readied action"? I'm trying to apply the rules equally and fairly to myself and my players, because I'm playing with someone who loves bending rules to their breaking points.
In my specific case, let's say a Paladin, with Mounted Combatant, has used Find [Greater] Steed. Can their mount, arguably an intelligent one, use readied actions? It could act before its rider, moving up to a foe, then ready the dash action for the moment after the rider strikes. Thus ending its turn, and allowing the rider to go, the rider could attack, after which point the mount can race away from the engagement.
By RAW, all creatures can ready an action. Same as they can attack, dodge, dash, etc. If you want to add additional conditions, as a DM, that’s something you can always do. But just saying everyone can keeps it simple, and is easy to remember.
In my specific case, let's say a Paladin, with Mounted Combatant, has used Find [Greater] Steed. Can their mount, arguably an intelligent one, use readied actions? It could act before its rider, moving up to a foe, then ready the dash action for the moment after the rider strikes. Thus ending its turn, and allowing the rider to go, the rider could attack, after which point the mount can race away from the engagement.
Yes, but ultimately they don't need to.
Without using ready you can have mount move to enemy, you can attack, the mount can use a Dash action to leave. No readying is needed.
While you’re mounted, you have two options. You can either control the mount or allow it to act independently. Intelligent creatures, such as dragons, act independently.
You can control a mount only if it has been trained to accept a rider. Domesticated horses, donkeys, and similar creatures are assumed to have such training. The initiative of a controlled mount changes to match yours when you mount it. It moves as you direct it, and it has only three action options: Dash, Disengage, and Dodge. A controlled mount can move and act even on the turn that you mount it.
An independent mount retains its place in the initiative order. Bearing a rider puts no restrictions on the actions the mount can take, and it moves and acts as it wishes. It might flee from combat, rush to attack and devour a badly injured foe, or otherwise act against your wishes.
In either case, if the mount provokes an opportunity attack while you’re on it, the attacker can target you or the mount.
Rollback Post to RevisionRollBack
Click ✨ HERE ✨ For My Youtube Videos featuring Guides, Tips & Tricks for using D&D Beyond. Need help with Homebrew? Check out ✨ thisFAQ/Guide thread ✨ by IamSposta.
The actions described in the basic rules/Player's Handbook are common to all creatures. A DM might choose to play creatures with differing mental attributes differently to reflect this fact. But that is a roleplaying decision, not something dictated by the rules.
For example it makes sense that a Hawk would use the Search action to look for prey, while a Rat would use the Hide action to try to avoid becoming lunch. Listing out the actions common to all creatures would bloat their stat blocks, so that is why they are not enumerated for every single monster.
A creature can take any actions unless noted otherwise, such as mounted combat, animal companion, findfamiliar or summoned creatures for example which may further limit possible actions one can take
An intelligent mount, such as a Nightmare, Pegasus, or Unicorn can easily ready an action, if they so choose and you have not commanded them to use their action to Dash, Disengange or Dodge.
Do not expect them to do so all the time. A nightmare for example, being a Fiend, should definitely attack any celestials as often as it can, including reading an action if available, as well as AoOs. But it will not do so to a random creature you are fighting.
In my specific case, let's say a Paladin, with Mounted Combatant, has used Find [Greater] Steed. Can their mount, arguably an intelligent one, use readied actions? It could act before its rider, moving up to a foe, then ready the dash action for the moment after the rider strikes. Thus ending its turn, and allowing the rider to go, the rider could attack, after which point the mount can race away from the engagement.
Yes, but ultimately they don't need to.
Without using ready you can have mount move to enemy, you can attack, the mount can use a Dash action to leave. No readying is needed.
While you’re mounted, you have two options. You can either control the mount or allow it to act independently. Intelligent creatures, such as dragons, act independently.
You can control a mount only if it has been trained to accept a rider. Domesticated horses, donkeys, and similar creatures are assumed to have such training. The initiative of a controlled mount changes to match yours when you mount it. It moves as you direct it, and it has only three action options: Dash, Disengage, and Dodge. A controlled mount can move and act even on the turn that you mount it.
An independent mount retains its place in the initiative order. Bearing a rider puts no restrictions on the actions the mount can take, and it moves and acts as it wishes. It might flee from combat, rush to attack and devour a badly injured foe, or otherwise act against your wishes.
In either case, if the mount provokes an opportunity attack while you’re on it, the attacker can target you or the mount.
Unfortunately, it doesn't work that way.
Each creature in a combat, including a controlled mount, has its own turn. Even if the mount goes on the same initiative as a character, it will take its complete turn either before or after the character's turn. This makes it impossible to have the mount ride in, allow the rider to attack, and then have the mount ride away because it is splitting the mount's turn around the character's turn.
"During a round, each participant in a battle takes a turn. The order of turns is determined at the beginning of a combat encounter, when everyone rolls initiative."
In addition, although the initiative of the mount "matches yours", it either goes before or after you. DM call as to whether you can change whether it goes before or after on a turn by turn basis but usually the initiative order is decided at the beginning of combat.
I believe the only class that has the ability to use a mount on their turn is the newer beast master ranger for a small character riding a medium mount.
----------
To the OP: RAW, the Ready action is available to any creature, UNLESS the rules say otherwise. Which is the problem here.
Looking at the rules for mounts cited above. A controlled mount can only take the Dash, Disengage and Dodge actions. A Controlled mount does not have access to the Ready action. This means that a controlled mount can NOT move in and Ready an action to Dash away after the character has made their attacks since Ready is not an available action for a controlled mount.
An uncontrolled, intelligent mount does have access to the Ready action. However, it also has its own separate initiative which makes it challenging to coordinate the movement of the mount with the attacks of the rider. An uncontrolled mount could move adjacent to a target on the mount's turn. However, the target could decide to move away if it's initiative is before the rider's initiative, leaving the rider without a target unless they dismount. Similarly, the uncontrolled mount can move and attack the target and if the target is killed then the rider would again have no target available unless they dismount and another target is within range OR they decide to stay mounted and use a ranged attack. In terms of coordinating with an uncontrolled mount, the RIDER can Ready an action to attack when the mount gets within range of a target. However, in this case the rider will forego any Extra Attacks they might have since a Readied Attack action gives only one attack.
------
Basically, RAW, the mounted combat rules are very simple, but are not a good model of the behavior people would expect from a mount. Additional text stating that the mount acts on the character's turn and not on their own turn in the combat is needed to get the feature to work more closely to what is expected but that is not what the rules currently state.
"Readying" an action is explained fairly directly in the player's handbook:
The question I have is, who and what is allowed to "ready" actions? Player characters, certainly, are permitted, and it seems very reasonable that NPCs, too can ready actions (the villains know that someone is robbing the fortress, and array their archers for a surprise attack when the throne room is breached). But how far can this "readied action" extend? Does it require a degree of intelligence, lending strategy and timing to their abilities? From a rules standpoint, is it necessary for a creature to have "Ready an action" among their options, along with a reaction option to "execute a readied action"? I'm trying to apply the rules equally and fairly to myself and my players, because I'm playing with someone who loves bending rules to their breaking points.
In my specific case, let's say a Paladin, with Mounted Combatant, has used Find [Greater] Steed. Can their mount, arguably an intelligent one, use readied actions? It could act before its rider, moving up to a foe, then ready the dash action for the moment after the rider strikes. Thus ending its turn, and allowing the rider to go, the rider could attack, after which point the mount can race away from the engagement.
By RAW, all creatures can ready an action. Same as they can attack, dodge, dash, etc.
If you want to add additional conditions, as a DM, that’s something you can always do. But just saying everyone can keeps it simple, and is easy to remember.
Yes, but ultimately they don't need to.
Without using ready you can have mount move to enemy, you can attack, the mount can use a Dash action to leave. No readying is needed.
I think you need to check the Mounted Combat rules.
Click ✨ HERE ✨ For My Youtube Videos featuring Guides, Tips & Tricks for using D&D Beyond.
Need help with Homebrew? Check out ✨ this FAQ/Guide thread ✨ by IamSposta.
The actions described in the basic rules/Player's Handbook are common to all creatures. A DM might choose to play creatures with differing mental attributes differently to reflect this fact. But that is a roleplaying decision, not something dictated by the rules.
For example it makes sense that a Hawk would use the Search action to look for prey, while a Rat would use the Hide action to try to avoid becoming lunch. Listing out the actions common to all creatures would bloat their stat blocks, so that is why they are not enumerated for every single monster.
However, with respect to your question about mounts such as Find Steed there are also the rules regarding mounted combat to consider. Most mounts act as a controlled mount and so while they are being ridden their initiative changes to match the rider and they are now limited to the Dash, Disengage, and Dodge actions. - https://www.dndbeyond.com/sources/basic-rules/combat#ControllingaMount
A creature can take any actions unless noted otherwise, such as mounted combat, animal companion, findfamiliar or summoned creatures for example which may further limit possible actions one can take
An intelligent mount, such as a Nightmare, Pegasus, or Unicorn can easily ready an action, if they so choose and you have not commanded them to use their action to Dash, Disengange or Dodge.
Do not expect them to do so all the time. A nightmare for example, being a Fiend, should definitely attack any celestials as often as it can, including reading an action if available, as well as AoOs. But it will not do so to a random creature you are fighting.
Unfortunately, it doesn't work that way.
Each creature in a combat, including a controlled mount, has its own turn. Even if the mount goes on the same initiative as a character, it will take its complete turn either before or after the character's turn. This makes it impossible to have the mount ride in, allow the rider to attack, and then have the mount ride away because it is splitting the mount's turn around the character's turn.
"During a round, each participant in a battle takes a turn. The order of turns is determined at the beginning of a combat encounter, when everyone rolls initiative."
In addition, although the initiative of the mount "matches yours", it either goes before or after you. DM call as to whether you can change whether it goes before or after on a turn by turn basis but usually the initiative order is decided at the beginning of combat.
I believe the only class that has the ability to use a mount on their turn is the newer beast master ranger for a small character riding a medium mount.
----------
To the OP: RAW, the Ready action is available to any creature, UNLESS the rules say otherwise. Which is the problem here.
Looking at the rules for mounts cited above. A controlled mount can only take the Dash, Disengage and Dodge actions. A Controlled mount does not have access to the Ready action. This means that a controlled mount can NOT move in and Ready an action to Dash away after the character has made their attacks since Ready is not an available action for a controlled mount.
An uncontrolled, intelligent mount does have access to the Ready action. However, it also has its own separate initiative which makes it challenging to coordinate the movement of the mount with the attacks of the rider. An uncontrolled mount could move adjacent to a target on the mount's turn. However, the target could decide to move away if it's initiative is before the rider's initiative, leaving the rider without a target unless they dismount. Similarly, the uncontrolled mount can move and attack the target and if the target is killed then the rider would again have no target available unless they dismount and another target is within range OR they decide to stay mounted and use a ranged attack. In terms of coordinating with an uncontrolled mount, the RIDER can Ready an action to attack when the mount gets within range of a target. However, in this case the rider will forego any Extra Attacks they might have since a Readied Attack action gives only one attack.
------
Basically, RAW, the mounted combat rules are very simple, but are not a good model of the behavior people would expect from a mount. Additional text stating that the mount acts on the character's turn and not on their own turn in the combat is needed to get the feature to work more closely to what is expected but that is not what the rules currently state.