A submission is any technique that compels an opponent to tap by threatening serious injury. BJJ submissions fall into two categories:
Chokes compress the carotid arteries (blood choke) or close the airway (air choke). Blood chokes — triangle, rear naked choke, bow-and-arrow — cause unconsciousness within seconds if not tapped; they are uncomfortable but safe when released promptly. Air chokes cause a slower, more uncomfortable response.
Joint locks hyperextend or rotate a joint beyond its natural range of motion: armbars target the elbow, kimuras and americanas target the shoulder, heel hooks and kneebars target the knee. Joint locks require careful training respect — the tap must come before the injury.
Training culture treats the tap as absolute: release immediately on any tap, verbal or physical. This norm protects both partners.