Discard stems, seeds, and ribs from 2 chiles and coarsely chop. Coarsely chop remaining chile including seeds (for a less spicy dish, seed half of chile before chopping).
Blend chiles with remaining ingredients except chicken in a food processor until a paste forms. Cut several 1-inch-long slits in each piece of chicken, then rub paste all over chicken, rubbing it into slits. Marinate, covered and chilled, at least 2 hours.
To cook chicken using indirect heat on a 22 1/2-inch charcoal kettle grill: Open vents on bottom of grill and on lid. Light a rounded chimney full of charcoal briquettes (about 100) and divide between 2 sides of grill, leaving a space down middle.
When charcoal turns grayish white (15 to 20 minutes from lighting) and you can hold your hand 5 inches about top rack for 3 to 4 seconds, grill chicken, skin sides down first, on portion of lightly oiled grill rack with no coals underneath, turning occasionally, until cooked through, 20 to 30 minutes.
To cook chicken using indirect heat on gas grill: Preheat all burners on high (until thermostat registers 500°F). Turn off 1 burner and reduce heat on other burner (or burners) to medium. (Thermostat should register 350 to 375°F.) Grill chicken, skin sides down first, on portion of lightly oiled grill rack over unlit burner, covered, turning occasionally, until cooked through, 20 to 30 minutes.
Cooks' notes: ·Chicken can marinate up to 1 day. ·If you aren't able to grill, you can roast jerk chicken, skin sides up, in 2 large shallow flameproof baking pans (1 inch deep) in upper and lower thirds of a preheated 450°F oven, switching position of pans halfway through roasting, until cooked through, 25 to 30 minutes. Then turn on broiler and broil chicken, about 4 inches from heat, until skin is browned and crisp, 2 to 3 minutes.