Mace of Smiting

You gain a +1 bonus to attack and damage
rolls made with this magic weapon. The
bonus increases to +3 when you use the
mace to attack a construct.
When you roll a 20 on an attack roll made
with this weapon, the target takes an extra
7 bludgeoning damage, or an extra 14
bludgeoning damage if it's a construct. If a
construct has 25 hit points or fewer after
taking this damage, it is destroyed.
(1d6 bludgeoning, 4 lbs)