When you attack an object with this magic sword and hit, maximize your weapon damage dice against the target.
When you attack a creature with this weapon and roll a 20 on the attack roll, that target takes an extra 14 slashing damage. Then roll another d20. If you roll a 20, you lop off one of the target's limbs, with the effect of such loss determined by the GM. If the creature has no limb to sever, you lop off a portion of its body instead.
In addition, you can speak the sword's command word to cause the blade to shed bright light in a 10-foot radius and dim light for an additional 10 feet. Speaking the command word again or sheathing the sword puts out the light.
Proficiency with a greatsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.
Notes: Damage: Slashing, Maximize Weapon Damage, Damage, Combat, Heavy, Two-Handed
Great Gilliad that is OP
I want
Ah yes, a very rare magical item that is no better than a regular greatsword other than a 1/20 chance of dealing 14 extra damage and a 1/400 chance of either halving a target's walking speed or stopping them from using two-handed weapons. If you're going to give this to your party at least give it a +1 to hit and damage.
Out of combat utitlity for a martial character is nice though. If you give this to your party make sure that you are alright with them using this to trivialize mundane obstacles such as locked doors, walls and other destructible portions of the environment.
"When you attack an object with this magic sword and hit, maximize your weapon damage dice against the target."
Thing hits for max damage every time.
As I said, out of combat utility is nice. Generally, when you want to destroy an object you're doing it out of combat. Yes, occasionally you need to destroy an object in the middle of combat.
For the most part, a character will destroy objects such as doors and the like *outside* of combat. Out of combat, taking two attacks or six attacks to destroy a door has very little difference because time is far less of a commodity.
I would certainly agree it's underpowered for requiring attunement. Works well as a early game vorpal sword-lite though.