Bolas

A Large or smaller creature hit by a bolas is restrained until it is freed. A bolas has no effect on formless or Huge or larger creatures. A creature can use its action to make a DC 13 Dexterity check, freeing itself or another creature within its reach on a success. The bolas has an AC of 10, 5 hit points, and immunity to all damage not dealt by melee weapons. Destroying the bolas frees the creature without harming it and immediately ends the bolas’s effects. While a creature is restrained by a bolas, you can make no further attacks with it.

Due to their unwieldy nature, bolas make ineffective melee weapons. Melee attack rolls made with them are made at disadvantage.