Brogue Wiki
A net falls from the ceiling!

When triggered, a net trap drops a net on the ground with a diameter of 7 spaces, centering on the trap's pressure plate. It acts much like a spider's web and ensnares the player and any other creatures that are caught in, or wander into it. While ensnared in a net, you are defenseless. Each tile affected by the net can entangle the player or an enemy for 2-5 turns, and any entity caught in the net has a 100% chance of being hit with any attack directed at it. Flying enemies are unaffected. The net itself is flammable but, oddly, will not catch fire if dropped into lava.

Your allies have no idea what a net is, have never seen a net before, and are are completely facinated by the strange combination of rope and knots. They just think it's the greatest thing ever. Their over-zealous curosity will lead them to get stuck in the same net again and again. Thankfully, your enemies are no smarter.

Net traps can be useful against any normally evasive mob, as it ensures that all your attacks will hit, even with weapons that are too heavy for you to have a chance with otherwise. If you pay close attention and learn the movement behaviors of pursuing mobs, nets can be an invaluable tool to helping go toe-to-toe with much tougher mobs.