You gain a +1 bonus to attack and damage rolls made with this magic weapon.
Giant's Bane (Requires Attunement). You must be wearing a belt of giant strength (any variety) and gauntlets of ogre power to attune to this weapon. The attunement ends if you take off either of those items. While you are attuned to this weapon and holding it, your Strength score increases by 4 and can exceed 20, but not 30. When you roll a 20 on an attack roll made with this weapon against a giant, the giant must succeed on a DC 17 Constitution saving throw or die.
The hammer also has 5 charges. While attuned to it, you can expend 1 charge and make a ranged weapon attack with the hammer, hurling it as if it had the thrown property with a normal range of 20 feet and a long range of 60 feet. If the attack hits, the hammer unleashes a thunderclap audible out to 300 feet. The target and every creature within 30 feet of it must succeed on a DC 17 Constitution saving throw or be stunned until the end of your next turn. The hammer regains 1d4 + 1 expended charges daily at dawn.
Proficiency with a maul allows you to add your proficiency bonus to the attack roll for any attack you make with it.
Notes: Stacking Bonus: Strength Score, Bonus: Magic, Bonus: Ability Score Maximum, Damage, Buff, Combat, Heavy, Two-Handed
I was trying to find some legendary items for my campaign and added this as a treasure but now I'm going to remove it from list of treasures seeing as how OP it is.
So this seems really underwhelming
A few changes and a returning property would really bring this mjolnir wannabe together
While you are attuned to this weapon and holding it, your Strength score increases by 4 and can exceed 20, but not 30
for some real fun, give it to an eldritch knight so he can get that booming blade damage on it
This takes an attunement slot. Why would you need to attune to a weapon and then still have it affect your character. At the very least, when you are attuned to an item then you should be immune to it's affects.
You do have to be holding it for the +4 Str bonus to apply so it doesn't necessarily increase carry cap and jump distance. Something to keep in mind.