Can I injure someone by slamming them into a wall?

Question

The answer to this question says that movement speed doesn't let you piledrive your target into the ground - no bonus damage to hitting an enemy into the ground.

I'm interested in finding RAW for a similar case: a player grapples an enemy, picks it up (as if to move it) and slams it into a nearby wall. It seems like the improvised weapon rules might be applicable (a dead enemy is a valid weapon) for attacking the wall, but that deals damage to the wall not the enemy. Furthermore, the natural consequence is that the player hits another enemy, rather than a wall/ground.

If there are no RAW, and there don't seem to be, I'd like some advice on a house rule. Balancing verisimilitude (hitting two people together certainly hurts them both) with balance (essentially picking two targets for each melee attack instead of 1) is the key feature.

Answer 1

Read the Grappler's Manual.

Now that you have done that, there are no RAW for using a person as a weapon. However, there are rules for Improvised Weapons (p. 147):

An improvised weapon includes any object you can wield in one or two hands, such as broken glass, a table leg, a frying pan, a wagon wheel, or a dead goblin.

In many cases, an improvised weapon is similar to an actual weapon and can be treated as such.

The ones that spring to mind are Club and Greatclub, however, these weigh 2 and 10 pounds respectively. Your average goblin is going to clock in at around the same as a Halfling (40 pounds); anything bigger will be correspondingly heavier. This suggests, at least to me, that the average goblin would be more difficult to wield as a weapon than a greatclub; particularly if it is not dead. So, its going to take two hands and its going to do the default damage (1d4) to whatever it hits.

Logic dictates that the weapon will take the same damage (1d4) as the target.

Answer 2

Attacking a grappled enemy by slamming it into a wall is a "similar forceful blow" under the unarmed strike rule:

Instead of using a weapon to make a melee weapon attack, you can use an unarmed strike: a punch, kick, head-butt, or similar forceful blow...

The ability to attack two targets during one turn is represented by features such as Action Surge, Extra Attack and Flurry of Blows. If you use such features to shove or strike multiple targets during the same turn, you can describe it as slamming the targets into one another. Most of the time it's just cosmetic detail, but really good cosmetic detail can be worth Inspiration!

Without such features, you're not enough of a brawler to pull off this stunt.

Answer 3

Best example I've had while running a game of 5e is that generally a weapon is going to do more than a forceful blow against a wall or such, however as a rule of thumb a slam against a wall will do 1d4 in my game but the creature being slammed gets an instant retaliatory strike (fighting out in blind rage) if he hits then he deals damage, combat as normal. But if he misses, the PC then gains an attack of opportunity which ended up being a dagger to the chest in my game. Adds a nice spicy twist to environmental combat I find and the Players seem to love it.