Smashing a creature into surface over distance?

Because falls are instant, w/ my newly gained 50ft flight I was thinking about:

1) Grapple attack creature under my weight limit

2) Fly them some distance into high ceiling for damage

3) Drop them for free for instant non Action fall damage

What damage might the ceiling smash do? cheers

None RAW. There are no general rules for "smashing things into other things" that aren't "your weapon" into "your target". Any damage you would impose would be homebrew.

laffingist, if it helps you somehow:

- warlock repelling blast into a wall
- Involuntary movement and obstacles
- Pushing an enemy against a wall or another opponent

I might consider "smack them into the ceiling" to be an unarmed strike, but D&D doesn't have any rules about momentum, so that's it.

Anyway, smashing them into the ceiling at speed without smashing yourself would be impossible if there were -- there'd be no way to brake suddenly just after they hit.

Moving a Grappled creature up against a wall or ceiling deals no damage per se, but if one wanted accomplish such as an improvised action the DM could tell whether its possible and what kind of D20 Test you need to make, if any. Another option could be to take the Attack action and make an  Unarmed Strike to reflect such forceful blow for example or use other improvised damage.

The fall damage could work, though keep in mind that when you’re grappling someone you need a free hand (so kind of hard if you’re sword and board, for example), and you move at 1/2 speed, so in one round, you’re looking at 25 feet up, max, so 2d6 of fall damage. So a greatsword but without an ability modifier or chance to crit.

The ceiling would do nothing, same as pushing someone into a wall does nothing.

Quote from laffingist >>

Because falls are instant, w/ my newly gained 50ft flight I was thinking about:

1) Grapple attack creature under my weight limit

Weight limit usually doesn't come into play and enemies don't often have a defined weight. Size limits are what typically restricts you.

Quote from laffingist >>

2) Fly them some distance into high ceiling for damage

3) Drop them for free for instant non Action fall damage

What damage might the ceiling smash do? cheers

The best option to model what you want would be to take the Grappler feat. This feat does a few things for you:

• Punch and Grab: While this would resolve the grapple and a damaging unarmed strike at the same time, before any movement, you could ask to flavor it as your maneuver. Either way, you have your grapple + damage.
• Fast Wrestler: This allows you to use your full movement while dragging a grappled foe. Instead of a 25-foot drop, you can arrange a 50-foot one.

There are potentially ways to further increase the impact (HA!) depending on your class, magic items, companions, and other factors.

Also, note that your speed is normally halved when dragging a grabbed character.

Quote from SmiteMakesRight_3_5 >>

Quote from laffingist >>

Because falls are instant, w/ my newly gained 50ft flight I was thinking about:

1) Grapple attack creature under my weight limit

Weight limit usually doesn't come into play and enemies don't often have a defined weight. Size limits are what typically restricts you. [...]

 Yeah, I agree. It was also mentioned in earlier threads about grappling:

Quote from Xalthu >>

You are introducing a complication (weight) that doesn’t matter according to the rules. Size category is all that matters in grappling. If you can grapple and move someone according to size rules, then you can. The target’s weight is irrelevant. So all you need to do is remove the complication you added, and everything works just fine.

Additionally, there is no information in the rules about how much any creature in the monster manual (or other sources) weighs. So that part is purely speculation. 

 
(2014/5e rules):

Quote from Plaguescarred >>

Dragging or carrying a grappled creature is not limited by the grappler's carrying capacity but by grappled creature's size.. 

While not official ruling, it is also what said Dev @JeremyECrawford The rule on moving a grappled creature (PH, 195) works regardless of a creature's weight. It cares about creature size. 

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.