How to house rule a 5E flying mount that turns hostile? [closed]

Question

My party is on borrowed mounts for a flying hunt. Unbeknownst to them, the "hosts" are aware of them as antagonists. I intend to have the hosts tell the flying mounts to dismount the party when they are some 50 feet up. I know from the PHB that forced movement of a mount calls for a DC 10 DEX check. I am just wondering if anyone might have some house rules that could spice things up a bit.

Answer 1

If there are saddles involved I would keep the DC 10 Dex check. If there are no saddles then I would go up a level of difficulty with a DC 15 Dex check.

As couple of points

• Start off by describing the mounts going crazy in the air and the party making DEX Check.
• If you feel generous make a secret Insight check for individual members to notice their mounts seem tense. Often when people are about to execute a betrayal they reveal a 'tell' that would give away that something is going down. The DC of the check would be based on how difficult you judge the characters being able to read the mount's mood.
• Likely it will take the players a round or two figure out that something really adnormal is going on. Since this is all done verbally give them a few extra moments for the first few rounds to talk and figure out stuff. Then crank it up after round 3 or 4 by giving them limited time to declare their actions before making the next DEX check.

What going to be critical is how you pace the out of game time cycle of players decision and DEX check. Too long and it is not really a challenge, too short they will think it is unfair.

Answer 2

Personally, I would use the shove rules for this. The mount is trying to throw the players off, while the players are trying to stop that. The creatures roll their strength (athletics), which the players counter with either strength (athletics) for holding on through sheer strength, or dexterity (acrobatics).

If you want to warn the players, you could roll deception against their passive insight. The reason you're using passive insight is because they didn't specifically ask a question that could be solved with a roll, and are not actively suspicious.

Answer 3

Applicable rules

There is no need for house rules; the RAW cover this, albeit very harshly.

A willing creature ... can serve as a mount

The creature is not willing, therefore you fall off.

Furthermore, the PHB also says:

If your mount is knocked prone, you can use your reaction to dismount it as it falls and land on your feet. Otherwise, you are dismounted and fall prone in a space within 5 feet it.

The creature can fall prone as part of its movement, therefore you are dismounted.

How I would handle it

1. Check for surprise, mount's Charisma (Deception) vs character's passive Wisdom (Perception)
2. Roll initiative, characters who are not surprised and beat their mount's initiative can use an attack to start a grapple.
3. On the mount's turn it:
   1. attempts to break any grapple, and
   2. falls prone; characters who have not grappled fall off.