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
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?