Chain of Bound Brothers (3.5e Equipment)
From D&D Wiki
The Chain of Bound Brothers is a ten-foot length of magical chain that binds itself around one limb of two characters. Once attached, the Chain cannot be removed by normal means. The blessings of some deities, the completion of a sacred mission, the physical breaking of the chain or the death of one of the bound parties will remove the effect. The two parties are bound to each other by this chain. The Chain is treated as a +3 Morningstar and either party may make an attack roll as if the other party were, in fact, the business end of a Morningstar (regardless of whether or not the other party made the Strength check). The size category of the player used as the Morningstar determines its size, weight and damage. They may still use any other one-handed weapons in addition to the Chain. Regardless of initiative rolls, whoever had the lower initiative of the two bound parties goes immediately after whoever had the higher initiative.
A character who is currently being "attacked with" may make a Grapple check upon a successful hit in order to grab the enemy, but, upon failing this Grapple Check, that player may also be Grappled by the target.
Both character may attempt to "clothesline" an enemy or group of enemies with the 10-foot chain. This is treated as a trip attack against all targets within range of the chain. If this technique is used on one character's turn, the other character skips his next turn.
One player may be thrown to a ledge a distance less than the length of the chain away by the other player. If that player makes a successful Climb check, the other player immediately makes their Climb check without rolling.
The Chain grants supernatural strength and endurance to the limbs which it is attached to to prevent them from being severed by anything other than magical weapons. In addition, if both characters are attempting to make any one Saving Throw, both characters gain +2 to resist. Any effect which would transport one of the wearers to another location (but which would not kill them) transports the other. If one character is between 0 and -10 hitpoints and bleeding, and the other character is above 1 hitpoints, the character who is below 0 hitpoints will not take bleeding damage.