5e Aerial Combat

My 5e game has taken some interesting twists and turns as I introduce this, that, and the other thing to keep things interesting. For example, the party has been dealing with a hobgoblin army that's surrounded a walled town. There aren't enough troops to take the town, and the town doesn't have enough troops to force away the army. Clearly both are awaiting reinforcements. But the PCs came from the same direction the hobgoblin reinforcements would be arriving from, and they didn't overtake anyone... So the force should be coming from some other direction... or by some means other than marching. Magic could work, but doesn't necessarily make for a good story.

Flying? That could work, plus sets up an interesting tactical challenge.

I already introduced a green dragon, but he's a selfish SOB. Wyverns don't get enough love, and with Reaper doing Blacksting the wyvern as part of Bones 4 I felt inspired to include some.


Source

Then my players asked me if there were any flying creatures in the town they were helping to defend. I'd actually figured they'd use the big weapons on the walls... but sure, why not. A small stable of hippogriffs that are used primarily as fast couriers.

Okay, so then to check aerial combat in the 5e books... and nothing. Hmmm... Rules cyclopedia? Also not really helpful. Okay, I guess we're just gonna wing it.

I basically decided that I was gonna riff on the idea that for the most part both the wyverns and hippogfiffs need to keep moving to keep flying. I decided that turning would cost 10' of movement, and reversing course would cost half move, except for the paladin's giant bat who I figure is more maneuverable. Altitude would be handled mostly by hand waving it. I used the hex grid, and called each space 10'

Playing on the Sultan... and not taking advantage of anything but the large surface area!

I pulled out 12d12 to represent the wyverns, and each player grabbed a figure to represent them and their mounts. I broke the wyverns into 2 waves of 6, and the second wave would show up after 1d6 rounds.

The players decided to sneak attack the wyverns. They have a magical top hat that's a portal to a large pocket dimension/demi plane, and had everyone and their mounts enter it, while the paladin and his bat were turned invisible by the bard. They'd fly right up to the hobgoblin's on wings, and dump everyone out in the midst of them.

The hobgoblins, loaded for attacking a city were unprepared for an aerial dogfight, so the players got a surprise round. Initially the players focused on the hobgoblins, not realizing just what asses the wyverns were by themselves.

Noting that the wyverns were fairly loaded down, the players asked a bit more about that. and I told them that some were carrying the same sort of oil barrels that the resupply caravan had. The dragonborn paladin positioned himself to breath fire on 2 that had the barrels (I decided the odd numbered ones had them) and let have it with his flame breath attack. One failed its save and caught fire, and then the bard dropped a fireball on them, and the other one fail its save. They both dropped from the fight.

Why do you do this to us?

Unfortunately the bard took a critical hit, knocking her from the back of the bat. She was saved from splatting with a featherfall., but then one of the hippogriffs suffered some massive damage and dropped. A series of aerial rescues, and acrobatic leaps onto wyverns as the battle progressed.

In spite of how well things were going, they were outnumbered, and once the hippogriffs started taking damage, things went downhill for the party fairly quickly. As quickly as they could, they retreated back into the hat. Well, those that could. The new Ranger who'd joined for this session was too far away, and being chased by 3 wyverns. He managed to kill one with Entangle, got a badly injured one to break off, and took the other from the hobgoblin rider when his hippogriff was killed. The paladin on the bat with the hat, entered the demiplane, leaving the hat to blow about in the wind 500' up, and within sight of the hobgoblins. Two of them spotted the hat, and one of them managed to snatch it from the air.

Thoughts:
Okay, 12 wyverns was probably too much. Breaking it into 3 waves of 4 might have been better. On the other hand, I love a fight that really challenges the party.
Lances need a better mechanic. 1d12 damage is nice... but on a charge should probably do more.
Writing the stats for the hippogriffs on the playmat so PCs could track their own mounts was smart of me.
Having some sort of directional marker to indicate which way everyone was flying would have been useful, as well as a way to indicate altitude.
How easy is it gonna be for the PCs to maintain control of the 2 wyverns they've captured???