Ball and Chain (3.5e Equipment)
From D&D Wiki
A Ball and Chain is a 10 Ft. long chain connected to a heavy round weight. The Ball and Chain has reach, so you can strike opponents 10 feet away 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.