RAW and RAI for grapplers

[Quoz]

Just starting a new character, a 1st level Firbolg monk. I want to focus on grapple, pin, and stun for battlefield control. I haven't played 5e for a while and I want to make sure that I understand how the rules differ from regular attacks and unarmed strikes to athletics checks as special melee attacks.

Are there any situations where I cannot substitute a shove or grapple for an attack, and how does this affect triggers? (especially in regards to martial arts bonus attack or flurry of blows)?

How does advantage work differently? Do things that work for attacks like prone or invisible still help? I know things like rage, hex and enlarge work since it is a skill check, but since it is a type of melee attack do things that specifically benefit melee attacks still work?

If I count as larger for encumbrance, as with the brawny feat, does that also work with the size of creature I can move without penalty in a grapple?

What other tricks should I think about as I progress? Can a Kensai with Tavern Brawler feat take choose improvised weapons as a Kensai weapon and use goblins as clubs? Can I use a grappled creature as cover?

[Varlon]

Are there any situations where I cannot substitute a shove or grapple for an attack, and how does this affect triggers? (especially in regards to martial arts bonus attack or flurry of blows)?

You can't replace any old attack with a grapple, only ones made using the Attack action, but it does count as taking the Attack action. You couldn't use the free Martial Arts attack because grappling is neither making an unarmed strike nor attacking with a monk weapon, but you could use Flurry of Blows since that only requires you to take the Attack action.


How does advantage work differently? Do things that work for attacks like prone or invisible still help? I know things like rage, hex and enlarge work since it is a skill check, but since it is a type of melee attack do things that specifically benefit melee attacks still work?

Stuff like invisibility and prone affect attack rolls, and grappling does not involve making an attack roll, so no. You're right that stuff that affects ability checks applies.


If I count as larger for encumbrance, as with the brawny feat, does that also work with the size of creature I can move without penalty in a grapple?

No, moving a grappled creature only cares about size, not weight.

[LeonBH]

The world of grapplers is fraught with DM rulings, because most DMs don't know the rules of grappling well enough.

You may only substitute grapple checks on your melee weapon attacks when you take the Attack action on your turn. This means no grapples on opportunity attacks, and no grapples on Flurry of Blows or Martial Arts bonus action attack.

Things that give disadvantage on attack rolls are completely bypassed by grapple checks. The Dodge action is negated by a grapple check because (1) it only imposes disadvantage on attack rolls, and (2) it ends as soon as the dodging character falls to zero speed, which being grappled does. Invisibility is also bypassed as long as you know which square the invisible enemy is in (assuming a grid), because it only imposes disadvantage on attack rolls.

Note this also means restrained, incapacitated, and paralyzed creatures do not make checks to resist grapples at disadvantage. They only make attack rolls at disadvantage (restrained), or auto-fail Str/Dex saves (paralyzed). So they can still beat you if they roll a high Athletics or Acrobatics check.

The Brawny feat does not increase your actual size, so if you are medium, you can still only grapple up to large creatures.

You could use grappled creatures as cover, but this comes with the DM's blessing. Most DMs I've played with do not allow it, and there is no RAW that says you can. So you have to be smart with positioning so that you're standing behind the creature you're grappling.

If you have the Tavern Brawler feat, everything you touch is a weapon, including goblins. But if they're still alive, the DM may not let you use them as weapons.

One trick to remember is Frightened causes checks to be made at disadvantage. This means Menacing Attack is deadly in the hands of a grappler.