Ball and Chain (3.5e Equipment)
From D&D Wiki
A Ball and Chain is a heavy round weight attached to a chain, 5 feet in lenght (per size). The Ball and Chain has reach, so you can strike opponents, at a distance equal to the chain, with it. In addition, unlike most other weapons with reach, it can be used against an adjacent foe.
The wielder of a Ball and Chain who also has the Power Attack feat may make a special attack action (A building of momentum strike as the Ball and Chain whirls around the wielders head gathering force.) if he has a base attack bonus of 6: As a full round action, the wielder may make a power attack of at least a -5 penalty (He still gets the benefits of Power Attack.) to add an additional 1d8 points of bludgeoning damage for a medium Ball and Chain (1d12 for a large Ball and Chain and so on...), and an expanded Critical of 19-20/x4. The additional bludgeoning damage is multiplied on a confirmed threat. If the wielder misses the attack he must make a Fortitude > Reflex save (DC 14) or fall prone due to a loss of balance. You can continue to build momentum if you desire increasing the critical multiplier and threat range by 1 each for every round spent building momentum. If you are attacked while building momentum you must make a Reflex save (DC 12) or lose the built up momentum and fall prone.