1/2tspcayenne pepperplus more for a stronger kick - see my notes
Start preheating the grill to medium high, about 300F-350F at the grate level.
Meanwhile, combine all of the ingredients except chicken in a medium bowl and mix well.
Pat dry the chicken legs with paper towel, then evenly apply the rub all over the chicken legs. The rub should stick to the chicken fairly easily without adding any oil. If not, rub the chicken legs with a small amount of oil then apply the rub. Set aside and let sit at room temperature until the grill is ready.
Brush the grill grate with a little bit of oil to prevent chicken legs from sticking. Place the legs on the grill, skin side down, and close the lid. Grill covered for about 30 minutes, flipping every 8-10 minutes and moving around to account for hot spots and ensure even browning. The legs are ready when the chicken legs are nicely browned and the internal temperature is reading about 180F-190F.
1/2 tsp of cayenne pepper will provide mild, pleasant spiciness 1 tsp - medium kick 1 1/2 tsp plus more - a lot of kick.