Ethereal Weapon (5e Equipment)
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Weapon (any melee weapon), rare (+0), very rare (+1), or legendary (+2) (requires attunement)
This magic weapon can phase in and out of the ethereal plane, allowing it to pass through armor and attempts to parry it. You have a bonus to attack and damage rolls made with this magic weapon. The bonus is determined by the weapon's rarity.
When you make a melee attack with an ethereal weapon, you can make an ethereal strike. Instead of making an attack roll, the target makes a Dexterity saving throw. On a failed save, the target takes the weapon's damage. The save DC is 8 + your Strength modifier + your proficiency bonus.
If the weapon has the finesse property, you may add your Dexterity modifier to the save DC instead of your Strength modifier.