Hi all, hoping to understand attack options - particularly if they play into ranged attacks and what the implication would be.

From dmg:

Disarm

A creature can use a weapon attack to knock a weapon or another item from a target’s grasp. The attacker makes an attack roll contested by the target’s Strength (Athletics) check or Dexterity (Acrobatics) check. If the attacker wins the contest, the attack causes no damage or other ill effect, but the defender drops the item.

The attacker has disadvantage on its attack roll if the target is holding the item with two or more hands. The target has advantage on its ability check if it is larger than the attacking creature, or disadvantage if it is smaller.

does this mean that you could use a ranged weapon attack to disarm? If so, does that impact if it’s defended by an athletics or acrobatic check? Also,would the advantage/ disadvantage of size still apply?

That rule only says "weapon attack" which means a ranged character could use it. If it said "melee weapon attack" that would be a different story. And using a ranged or melee weapon wouldn't affect how the rule is used because it doesn't stipulate either way.

It wouldn't affect how it's defended either. Whether the target uses an Athletics or Acrobatics check is up to them - not the person making the attack (just like with the Shove rule).

thanks so much - follow up q: Is the defender doing a dex/str check or a skill check?

The defender will be doing a Strength (Athletics) ability check or a Dexterity (Acrobatics) ability check vs the attack roll of the attacker. In 5e there's no such thing as a 'skill check'.

A Strength ability check just adds the Strength modifier to the d20 roll. A Strength (Athletics) ability check adds the Strength modifier and also the Proficiency modifier if they are proficient in the Athletics skill (and again if they have Expertise). Calling the latter a skill check is technically a misnomer.

 I believe you are aware of this because you called them "attack options", but just in case keep in mind that the Disarm attack is an optional rule found in the DM Workshop section of the DMG.  Make sure to check with your DM if they'll actually allow you to do this action.

I had this very same train of thought. And as this is a DMG optional rule. As a DM I would rule that Disarm at range would constitute disadvantage and be situational at best. Say in the instance of using a sling to disarm an opponents shield. Seems a little far fetched. I would rule that a sling or even an arrow/bolt would not be able to impose disarm on a shield hand as even if he is facing away or distracted shields are generally kept close to the body and protected at the wrist. However in Melee combat it is very common to disarm a shield. Or hook it with a pike etc. And so I would allow it. But say for a longsword or a crossbow being trained to fire and being targeted by a disarm ranged attack I would rule that it would be possible at disadvantage. situationally as well of course. Perhaps even benefitting from the Cover rules. As you are targeting the Wrist of a basket rapier or sabre that offers good protection perhaps the wrist benefits from +2/+5 AC in the form of a plus to the ability check save.

Actually I don’t know if, melee or range, you can disarm a shield. It is not held it is worn and has donning and doffing rules. So unlike an item like a weapon that you can drop as a “free” action you need to doff a shield that take 1 action. 

You can rule that disarming at range has disadvantage but it’s not RAW. And heck, if someone can shoot a gun out of another persons hand like you see in some American western movies, why not allow it in a fantasy game.