06 Feb Grapple 5e D&D Guide 
Keeping an enemy from running away or jumping on the back of a large creature both require a player to grapple. This guide covers how grapple works when it should be used and why you should do it more often.
The rules for using a Grapple are found in the Players Handbook on page 195.
When you want to grab a creature or wrestle with it, you can use the Attack action to make a special melee attack, a grapple. If you’re able to make multiple attacks with the Attack action, this attack replaces one of them.
The target of your grapple must be no more than one size larger than you and must be within your reach. Using at least one free hand, you try to seize the target by making a grapple check instead of an Attack roll: A Strength (Athletics) check contested by the target’s Strength (Athletics) or Dexterity (Acrobatics) check (the target chooses the ability to use).
You succeed automatically if the target is Incapacitated. If you succeed, you subject the target to the Grappled condition. The condition specifies the things that end it, and you can release the target whenever you like (no action required).
The rules for grappling clearly define this as a special attack that is part of the attack action. It replaces one of the attacks you can make (provided you can make more than one), not the whole action. It is possible for a fighter with two attacks to grapple an enemy and then stab them with a weapon.
The Grappled Condition
A grappled creature’s speed becomes 0, and it can’t benefit from any bonus to its speed. The condition ends if the Grappler is incapacitated. The condition also ends if an Effect removes the grappled creature from the reach of the Grappler or Grappling Effect, such as when a creature is hurled away by the Thunderwave spell.
Escaping a Grapple
A grappled creature can use its action to escape. To do so, it must succeed on a Strength (Athletics) or Dexterity (Acrobatics) check contested by your Strength (Athletics) check.
Moving a Grappled Creature
When you move, you can drag or carry the grappled creature with you, but your speed is halved unless the creature is two or more sizes smaller than you.
What is the Point of Grappling?
Grappling itself does not do any damage but can be a useful tactical asset. When a creature is grappled, they are under the grappled condition. Their speed is 0.
It takes a full action to attempt to break free of a grapple. So, when you tie up that enemy caster or warrior, they have a decision to make. A failed escape attempt still takes their action. This can allow you to get a free round even if they manage to escape.
You can also use grapple to move creatures and prevent them from moving. A grappled creature’s speed becomes 0, so the villain that tries to escape with the loot doesn’t get far. It could also be handy to put creatures in a cage or prisoners in a cell if they are less than cooperative.
Grapple, according to rules as written and confirmed by Sage Advice, cannot be used as an attack of opportunity. It is a widely accepted house rule to allow it, though, so it may be worth it to confirm with the DM.
What does the Grappler Feat do?
Grappler – Players Handbook page 167
The prerequisite for the Grappler feat is a Strength 13 or higher
You’ve developed the skills necessary to hold your own in close-quarters grappling. You gain the following benefits:
You have advantage on attack rolls against a creature you are grappling. You can use your action to try to pin a creature grappled by you. To do so, make another grapple check. If you succeed, you and the creature are both restrained until the grapple ends.
Breaking a Grapple with Magic
The grappled condition states, “The condition also ends if an effect removes the grappled creature from the reach of the grappler or grappling effect, such as when a creature is hurled away by the Thunderwave spell.”
Simple right? The grappled individual casts Thunderwave. The grappler fails the constitution check and is pushed 10 feet away breaking the grapple.
This can create an interesting scenario when a 3rd party gets involved, however.
There is a grappler and a grapplee. A caster approaches within 5 feet of the pair and casts Thunderwave. The grappler passes the constitution save, so he stays put. The grapplee fails the constitution save, so he gets pushed 10 feet away from the caster and the grappler. Right? Technically yes. The grapplee is moved out of the range of the grappler per the spell. This means the grapple condition is lost.
A possibility in this scenario could be to give the grappler an Athletics (STR) check vs. the Spell DC. A pass would mean the grappler held on to the grappled individual, and a failure would mean a release. Always defer to the DM and respect their decision.
Grappling and the grappled condition are important and value-added parts of the game. They can create some confusion and some chaos, though. It seems to be something that comes up all the time or almost never. Grapple, much like many other special features in the game, can add excitement to an otherwise average scenario.