With one precise stab, you hamper movement.
Benefit(s): As a standard action, make a single attack with your chosen weapon. If the attack hits, the target’s movement speed is halved until the start of your next turn. When your base attack bonus reaches +11, the target’s movement is so hampered that even a 5-foot step provokes an attack of opportunity. When your base attack bonus reaches +16, the target must also succeed at a Reflex save with a DC equal to 10 + your base attack bonus or become entangled. An entangled creature’s movement can be halved only once. You can use this feat’s benefits only once per minute.
Pathfinder Player Companion: Martial Arts Handbook © 2018, Paizo Inc.; Authors: Thurston Hillman, Mikko Kallio, Jacob W. Michaels, Matt Morris, Daniel Reed, Mikhail Rekun, Mark Seifter, and Jeffrey Swank.