Mithral Weapons

Quote from Wysperra >>

So Adamantine Armor has special properties, Adamantine Weapons have special properties.

Mithral Armor has special properties, but Mithral Weapons do not.

Any suggestions as to what I could include in my game? Nothing game breaking just a little something to make them better than run of the mill weapons.

Thanks!

 5.5e adamantine weapons are already insanely broken, especially since they're only classified as "uncommon." When combined with barbarian's Brutal Critical and one of the Slasher/Crusher/Piercer feats, you do massive, debilitating damage with every strike. Just give mithral weapons an equally broken ability that's the opposite of the armor version like adamantine is; something like ignoring all cover, invisibility, and illusions like a Mirror Image spell or a Cloak of Displacement, or even just the ability to always hit a target.

Quote from Jacob228 >>

Quote from Wysperra >>

So Adamantine Armor has special properties, Adamantine Weapons have special properties.

Mithral Armor has special properties, but Mithral Weapons do not.

Any suggestions as to what I could include in my game? Nothing game breaking just a little something to make them better than run of the mill weapons.

Thanks!

 5.5e adamantine weapons are already insanely broken, especially since they're only classified as "uncommon." When combined with barbarian's Brutal Critical and one of the Slasher/Crusher/Piercer feats, you do massive, debilitating damage with every strike.

I suspect you have misunderstood how an Adamantine Weapon works. From the item's description:

Whenever this weapon or piece of ammunition hits an object, the hit is a Critical Hit.

The automatic critical thing only applies when you're attacking an object. It does not apply when you're attacking a creature. Attacking objects is fairly rare in D&D and the ability to do extra damage to them isn't "insanely broken".