▁Blue ▁D ice ▁( Bo ost ▁Die ) ▁( a ▁ 6 - s ided ▁light - blue ▁die ▁with ▁black ▁mark ings ) ▁are ▁used ▁to ▁aid ▁a ▁skill ▁roll ▁due ▁to ▁advantage ous ▁factors . ▁They ▁only ▁have ▁Success , ▁Adv antage , ▁and ▁blank ▁faces . ▁Char acters ▁with ▁equal ▁or ▁greater ▁skill ▁can ▁take ▁an ▁action ▁to ▁aid ▁another ▁Character ▁who ▁is ▁using ▁a ▁skill ▁to ▁perform ▁a ▁task ▁by ▁grant ing ▁them ▁a ▁blue ▁die . ▁▁▁ ▁Black ▁D ice ▁( Set back ▁Die ) ▁( a ▁ 6 - s ided ▁black ▁die ▁with ▁white ▁mark ings ) ▁are ▁used ▁to ▁pen al ize ▁a ▁skill ▁roll ▁due ▁to ▁dis adv antage ous ▁factors . ▁They ▁only ▁have ▁Fail ure , ▁Th re at , ▁and ▁blank ▁faces . ▁Character ▁ant agon ists ▁with ▁equal ▁or ▁greater ▁skill ▁can ▁take ▁an ▁action ▁to ▁dis rupt ▁another ▁Character ▁who ▁is ▁using ▁a ▁skill ▁to ▁perform ▁a ▁task ▁by ▁pen al izing ▁them ▁with ▁a ▁black ▁die . ▁Per cent ile ▁D ice ▁( C rit ical ▁D ice ) ▁( a ▁pair ▁of ▁ 1 0 - s ided ▁dice ▁that ▁are ▁different ▁colors ; ▁one ▁color ▁is ▁the ▁" t ens " ▁digit ▁and ▁the ▁other ▁color ▁is ▁the ▁" ones " ▁digit ; ▁" 0 1 " ▁is ▁equal ▁to ▁ 1 ▁and ▁" 0 0 " ▁is ▁equal ▁to ▁ 1 0 0 .) ▁These ▁are ▁mostly ▁used ▁to ▁roll ▁on ▁the ▁Crit ical ▁In