When attacking, treat bolas as a thrown weapon with the same range increments as flaming oil or holy water. A successful hit inflicts no damage but binds the target’s legs together. An entangled target can only move 3’/round and must save vs. paralysis each round or fall prone. Removing the bolas takes a full round of action and requires at least one free hand. (If a character is in no position to unwrap the bolas manually, he may attempt to snap the cord or chain with an Open Doors check.)
As a rule, only classes that can use all weapons, such as fighters, halflings, dwarves and thieves, may use bolas, and even then they require some training in their use.