The grappling rules do not say anything about size other than that you cannot grapple something two or more sizes larger than you, and that your speed is halved during a grapple unless the grappled creature is two or more sizes smaller than you. By RAW, no advantage due to size is granted for any grapple checks.
Do you get advantage on a grappled target?
A grappled creature’s speed becomes 0, and it can’t benefit from any bonus to its speed.
Can you grapple multiple people?
The way the rules are written there is no harder check for multiple people attempting to grapple. Each successful grappler will have the target grappled potentially necessitating multiple athletics checks to escape.
How does grappling work in a skill contest?
Grappling is a skill contest that imposes the grappled condition. Effectively, all the grappled condition does is reduce your speed to zero. In order to give this any real teeth, you must knock the grappled target prone. 5e grappling mechanics are simpler than prior editions.
How many weapons can you use while grappling?
Attack Your Opponent: You can make an attack with an unarmed strike, natural weapon, or light weapon against another character you are grappling. You take a –4 penalty on such attacks. You can’t attack with two weapons while grappling, even if both are light weapons.
How many opponents can you grapple in one round?
Up to four combatants can grapple a single opponent in a given round. Creatures that are one or more size categories smaller than you count for half, creatures that are one size category larger than you count double, and creatures two or more size categories larger count quadruple.
Can you replace bonus action attacks with grapples?
You cannot replace bonus action attacks (e.g. from the Monk or a Barbarian’s Frenzy) with grapples. A grapple check is an Ability check contested by a target’s ability check. It is NOT an attack roll! Your grapple target “must be no more than one size larger than you”.
