At least TWO armor components below the waist (codpiece, a set of thigh, a set of knee, a set of shin, and/or a set of foot armor). Pairs of armor like thighs, knees, shins, and boot are considered ONE piece as a set.
Knee armor is required. Knee coverage may be hard or soft, but must be "in universe" and high-quality. Extended shins that cover knees also count as knee armor.
Knee armour is compulsory?
Would TK lower leg armour be a good substitute?