When you roll a 20 with this magic weapon, the target takes an extra 7 Bludgeoning damage.
Note: According to the SRD, it is an extra 2d6 Bludgeoning damage, although this is incorrect.
This magic weapon deals an extra 2d6 damage to any creature it hits. This extra damage is of the same type as the weapon's normal damage.
If you hit a creature with this weapon, that creature has Disadvantage on its next attack roll before the start of your next turn.