Mounted Combatant + Sanctuary. What happens?

[Man_Over_Game]

I cast Sanctuary on myself. I also have Mounted Combatant and I'm riding a mount. Someone goes to attack my mount, and it targets me instead. Sanctuary causes the target to attack something else or waste his turn. What happens?

[Zhorn]

I cast Sanctuary on myself. I also have Mounted Combatant and I'm riding a mount. Someone goes to attack my mount, and it targets me instead. Sanctuary causes the target to attack something else or waste his turn. What happens?

First, it causes your DM to become Reverend Lovejoy

https://www.youtube.com/watch?v=7Hpz4iqYhZ8

But being that the wording of Sancuary specifies "new target" but not "creature", attacksing a object or the ground might be a valid ruling if there are no other creatures around to be valid targets beyound you and the mount? Either that or it just ping-pongs back and forth until one of the rules expires

Enemy targets mount
Rider chooses Mounted Combatant to force the attack to redirects to them self
Sactuary imposes a Wisdom save on the enemy (fails)
Sanctuary redirects the enemy's attack to the next valid target (back to the mount)
Rider chooses Mounted Combatant to force the attack to redirects to them self
Sactuary imposes a Wisdom save on the enemy (fails)
Sanctuary redirects the enemy's attack to the next valid target (back to the mount)
Rider chooses Mounted Combatant to force the attack to redirects to them self
Sactuary imposes a Wisdom save on the enemy (fails)
Sanctuary redirects the enemy's attack to the next valid target (back to the mount)
Rider chooses Mounted Combatant to force the attack to redirects to them self
Sactuary imposes a Wisdom save on the enemy (fails)
Sanctuary redirects the enemy's attack to the next valid target (back to the mount)
and on and on and on and on.
... either ...
A)
Rider chooses Mounted Combatant to force the attack to redirects to them self
Sactuary imposes a Wisdom save on the enemy (succeeds)
Enemy's attacks the rider

or B)
Rider chooses not to use Mounted Combatant to force the attack to redirects to them self
Enemy's attacks the mount

[Mith]

Away from book, but if the Mounted Combat feature is a reaction, then the above cycle only goes one iteration and then the mount is targeted. Otherwise they succed their, and the rider is targeted anyways.

[Eragon123]

Is is a great and fun question.

First we will assume that this a human fighter on a mundane mount.

The enemy targets the horse. You force him to target you. Notably this is not an attack, spell, or damage. Sanctuary now kicks in and forces the creature to make a save. If the enemy makes the save, he will attack you. If they fail the save, they would technically have a choice which could be ruled that it would cycle until the enemy either targets a third party or more reasonably loses the attack.

But let's say that you are a paladin and cast sanctuary while mounted on the result of your Find Steed spell. The enemy targets your horse. It makes a save, if it succeeds, you can force it to target you. If it fails, then targets you. When it targets you after either failing or succeeding on the save, you can force it to make another save. If it succeeds, it can attack you. If it fails, I'd rule it as either needing a third target or losing the attack. But another loop is technically possible.

[Zhorn]

...but if the Mounted Combat feature is a reaction...
Double checked and my book doesn't say reaction, so unless it's in an errata, look like a loop.

[Alucard89]

Why not just cast Sanctuary on your mount and enjoy enemies not being able to attack it. As long as it also does not attack or cast spell - your mount is really well protected:

"If the warded creature makes an attack or casts a spell that affects an enemy creature, or deals damage to another creature, this spell ends. "

Sacntury is great for mounts as they only..well... serve as car.

[Yunru]

Presuming your mount is always chosen as the new target, you get hit.
As long as they can save on at least one of the numbers on the die, you're just giving them unlimited rolls to get that number.

[Rukelnikov]

Presuming your mount is always chosen as the new target, you get hit.
As long as they can save on at least one of the numbers on the die, you're just giving them unlimited rolls to get that number.

You get attacked, not necessarily hit, but yeah, the attacker gets his attack one way or the other.

On a similar train of thought I've been thinking, lets say I cast Dragon Breath on my familiar, and Sanctuary myself, can I have it spew fire on my enemies without breaking Sanctuary? Then in that case, if I'm the one dealing the damage, does that mean I can cast sanctuary on my Familiar and him spew fire with impunity??

[Yunru]

You get attacked, not necessarily hit, but yeah, the attacker gets his attack one way or the other.

On a similar train of thought I've been thinking, lets say I cast Dragon Breath on my familiar, and Sanctuary myself, can I have it spew fire on my enemies without breaking Sanctuary? Then in that case, if I'm the one dealing the damage, does that mean I can cast sanctuary on my Familiar and him spew fire with impunity??
You mean cast Dragon Breath through your familiar onto your familiar, right?
The familiar would be doing the offensive thing, although I'd have to check the wording of Sanctuary to ses if that would end it.