Potential complications from allowing Arms of the Astral Self to interact with Grapple Rules via feats?

Question

Preface

My earlier question led to a definitive RAW answer proving that Arms of the Astral Self can't be used for grappling, even if a feat like Tavern Brawler gave you a grapple check bonus action off of the unarmed strike provided by it.

However, I'm the DM at the table, and in my head this is absolutely a Rule of Cool situation; neither Tavern Brawler nor the Grappler feat is assessed as particularly potent in community sources such as RPGBot, thanks to the fact that requiring a hit to trigger a grapple adds an extra chance for failure to the grapple not normally present, and the freely available grapple+shove combo that can be achieved in a single action instead of two for the same pair of grapple checks provided in Grappler, the latter of which leaves you Restrained as a result. This is a subjective opinion, but for the sake of the game I'm running, I agree, and character in question took both feats with clear intentions for a specific type of kit to provide synergy with a core concept of the character.

Specifics

I intend to alter the reach requirements to grapple on the bonus action grapple attempt provided by Tavern Brawler off of Arms of the Astral Self's unarmed attacks - reach for this grapple will be extended by 5 feet until broken, and the 'hands' of Astral Arms are likewise considered capable of establishing and maintaining a grapple (at regular reach, except when using Tavern Brawler's bonus action).

Grappler will work on any already-grappled target, including those grappled at 10 feet with Arms. All other grappling rules, including dragging a creature, shoving, escape rules, releasing, and effects that would move the target of the grapple outside that 10 foot range, will function normally.

Question

What potential complications or disruptions with other rules might this alteration cause, if everyone at the table is good beforehand with understanding that this is a unique Rule of Cool, and not a precedent to start breaking other things?

I'm looking specifically at possible mechanics and situations that have no readily actionable RAW resolution as a result of this change being utilized in combat, so I can prepare for such potential surprises before such a scene happens and not bog down the experience with having to come up with a complicated arbitration on the spot.

Answer 1

Be prepared for what it means to handle a grapple at reach

If I understand you right, your house-rule is that the character can attempt to grapple if they hit with a 10 foot-reach unarmed strike attack, and if they successfully do so, for that grapple, the character's reach is considered to extended by 5 feet (normally, it will be 10 feet), but not for any other purpose, only for as long as the grapple is successfully maintained.

You also leave the other requirements for the grapple in place (target cannot be more than one size category larger, you need a free hand to maintain the grapple which in this case is one of the astral hands.)

The first issue that I can see is what happens if the Arms expire. They have a limited duration of 10 minutes. I think that this can be easily addressed by stating that since the creature is grappled by these arms, the grapple automatically ends when they end.

Second, if they move closer to 5 foot reach, you should think about if you are OK that they just transfer the grapple to a normal free hand, or if they would need a new grapple attempt for that.

The third issue are all the normal complications a grapple with reach has and that need resolution. For example: How much can a grappler with reach move a grappled creature inside its reach?, If I am grappled by an enemy with 10' + reach, how does our movement work?, If you are grappled by a creature with 10'+ reach, can you make a ranged attack without disadvantage?, Can a Grappler move freely without moving the grappled creature and breaking the grapple condition?, Can a reach-grappled Creature melee attack the grappler?. These are not really specific to your situation, but you should be prepared for them, if you want to be ready with RAW resolutions.

Answer 2

No one can identify all the possible edge cases, but that doesn't matter.

You've got something that you want to allow as the DM - so allow it! You've got general ideas here about possible risks and that it's not RAW, but the only thing matters is if it works at your table.

And the only way to know that is it to try it. Just let the table and the specific player know that you may tweak things if it seems unbalanced and you'll explain the tweak so it's not just an out of the blue ruling/nerf.

Whether you are homebrewing, houseruling, or whatever - the best way to figure out if it's okay is to try it out. Keeping an open communication with the table also works, and don't be afraid to adjust and talk about it!

The rules are just a structure, allow you and your table to play with the structure and you'll have as much fun as on a playground.

Answer 3

The most obvious complication is: if your character grapples an enemy soldier from ten feet away, can the soldier still attack the character in melee?

We have an existing question about this, with answers supporting both sides.

Rules As Written, the answer appears to be: no, the person being grappled cannot attack unless they have something that is usable from ten feet away. (This is, by the way, pretty broken, and you should be very cautious about allowing it in your game.)

There's an unofficial Crawford tweet that says the person being grappled can still attack "the grappling appendage" using a melee attack. Be prepared for your character to argue that their Astral Arms are not part of their body and therefore cannot be usefully attacked.