In addition to DR, all armors have a Flex and Pad rating. The higher the Flex of the armor, the stiffer it is and the less of the damage it stops is transmited to the wearer. For every full multiple of Flex of basic damage stopped by the armor, one point of crushing damage is delivered. Pad is a measure of the amount of padding the armor has, it acts like DR to stop the blunt trauma.
Crushing, cutting, and impaling damage all cause full blunt trauma. Piercing damage is halved for the purpose of calculating blunt trauma. Other kinds of damage do not cause blunt trauma.
Large area attacks, such as those produced by most falls and collisions, treat all armor as if it were Flex 1 - in effect, subtract only the Pad from the damage.
Anything that has bought the advantage Damage Resistance (p. B46) is assumed to have enough Pad to deal with all the damage soaked up by the armor. Armor bought with the Flexible limitation has Flex 2 and no Pad. Extra Flexible armor is a -40% limitation, giving Flex 1 and no Pad. Partially Flexible armor is a -15% limitation for Flex 3, -10% for flex 4, and -5% for Flex 5. To represent armor with Pad, buy DR equal to Flex*Pad, then buy additional armor with the appropriate Flexible limitation.