The ranger has to use an action to tell his animal companion to attack Once they give that command do they have to repeat it every round?
If so why wouldn't they just get a guard dog that would do just that after a few months of training?
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Sign up to join this communityThe ranger has to use an action to tell his animal companion to attack Once they give that command do they have to repeat it every round?
If so why wouldn't they just get a guard dog that would do just that after a few months of training?
Technically, you have to use your action to tell your companion to do anything except move. From the PHB, page 93:
On your turn, you can verbally command the beast where to move (no action required by you). You can use your action to verbally command it to take the Attack, Dash, Disengage, Dodge, or Help action.
It says nothing about the animal companion continuing to perform the action you made it do in subsequent rounds. If you want it to keep attacking, you have to keep giving it orders. Effectively, it acts as a surrogate for you in combat. Note that, as pointed out in this answer, the Animal Companion isn't substantially weaker than the Ranger himself, and might actually be stronger, particularly at low levels.
I've seen the houserule that the Animal Companion should continue to attack an enemy once ordered to attack them once suggested quite frequently, and the DM is of course free to decide that this is the case. But this is still a houserule, not RAW.
As for "why wouldn't they just get a guard dog that would do just that after a few months of training", there is currently no explicit option that allows you to do this. You can buy beasts (including a mastiff) that are trained as mounts, but buying/training a dog to attack your enemies (which may include dragons, elementals, ghosts...) is entirely up to the DM. Even if they allow it, such a dog wouldn't get the bonuses that the Animal Companion gets and would therefore be weak at low levels and very quickly become effectively useless.
If so why wouldn't they just get a guard dog that would do just that after a few months of training?
In previous editions, this has been the case, but it's really a problem of economy.
D&D combat is really about the "action economy".
More actions = more good stuff. In fact, optimization in Pathfinder and 3.5 was heavily focused on making sure you could do as much as possible each round. Druids had the best of it with summoned/conjured creatures and an animal companion, a Druid could quickly be operating a small army on their turn. Get the Wizard to cast Haste and it got ugly really quickly.
D&D 5, scales back on this kind of craziness by limiting the number of actions a player can effectively do in a turn. You can get a Bonus Action on your turn, but you can only get one. And that Wizard who is casting Haste has to concentrate on Haste so they can't also cast Web. You can't conjure multiple time because you need to concentrate on the ones you have summoned.
The animal companion costs you an action for this same reason.
Having an animal companion that can attack every round puts the Ranger one attack ahead of everyone else at level 3. That's a big deal and so the rules have been written to prevent this from happening.