If a creature attacks a target warded by Sanctuary but fails the save, do they lose the attack/spell if there is no other target immediately in range?

Question

Take a simple scenario as an example:

• A cleric casts sanctuary
• An enemy wielding a spear attempts to make a melee attack at the cleric with his spear
• The enemy fails his Wisdom save, and thus can't attack the cleric

Now what?

According to the sanctuary spell description:

On a failed save, the creature must choose a new target or lose the attack or spell.

No one else is currently in melee range, but others are within move distance.

What happens to the enemy's intended attack, after failing the Wisdom save?

• Do they simply lose the attack if there is no other target immediately in range, causing that spear attack to be wasted?
• Does the enemy now get to "hold" the melee spear attack, use movement to get in melee range with someone else, and then resume the same melee spear attack on the new target?
• Can the enemy choose to make a different kind of attack with the same weapon, and decide to throw the spear instead (at someone else)?
• Can the enemy choose to attack with a different weapon, such as a shortbow, and attack someone else instead (either before or after moving)?
• Can the enemy choose to cast a spell instead of making a weapon attack?

Answer 1

If no one else is in melee range, then there is no longer a valid target for the attack, and the attack is lost.

The description of the Sanctuary spell says (emphasis mine):

the creature must choose a new target

...not that the creature gets to change the attack or make a new attack.

The type or “method” of attack has already been chosen – a melee attack with a spear – and Sanctuary does nothing to change that. You can’t change the attack to a ranged attack with the spear, you can’t swap weapons and change the attack to a ranged attack with a bow, and you can’t suddenly decide to cast a spell.

As for "holding" the attack and moving so that you can attack another creature, you can’t do that either.

The PHB states the following, under "Breaking Up Your Move" (bold for emphasis mine):

You can break up your movement on your turn, using some of your speed before and after your action.

[...]

If you take an action that includes more than one weapon attack, you can break up your movement even further by moving between those attacks.

Since this takes place during an attack, during an action, you’re unable to move.

Answer 2

No, they don't.

Consider an attack spell like eldritch blast which can target multiple characters. You have to pick all of your targets at the time of casting, and all blasts fire simultaneously. If you pick a target who is protected by sanctuary at the time of casting, you have to choose a new target immediately. You can't fire off a couple of blasts at non-sanctuary targets and then move around before firing off the last blast, since all of the blasts fire simultaneously. You also can't put the spell on hold until you've moved. You have to pick the new target immediately or lose the attack entirely.

The opening question was regarding a melee weapon attack and not a spell attack, but the rules for attacking are essentially the same regardless of what kind of attack is being made.

Answer 3

So does the enemy now get to HOLD the melee spear attack, use a move action and then resume the same melee spear attack on someone else?

Personally I'd say they can't hold the attack. I envision the spell as the character is mid-swing and it's been declared that they will miss, they now have a short window of opportunity to redirect their attack.

However, holding their attack and moving appears to follow the "letter" of the spell so it's possible for a DM to allow this.

Can the enemy change the attack method of the spear melee attack and decide to throw the spear instead?

I'd say this is reasonable as it's still the same weapon and the attack isn't being held, but some DMs may consider this a different type of attack.

Can the enemy change his attack method to a short bow attack and attack someone else instead either before or after a move with a different weapon?

Can the enemy choose to change his attack method to a spell?

I don't often play with any hindrance for switching weapons (because I forget) but some DMs do. For instance it might take a bonus action or even an action to sheath one weapon and draw another.

Also in general this sounds like a bit much. Since the Player's Handbook says "on a failed save, the creature must choose a new target or lose the attack or spell" it sounds like you merely have the option to redirect the attack, not make a new attack with a new weapon/spell. If you switch the weapon being used then it sounds like that original attack has been lost.