▁for ▁such ▁black mail ▁to ▁be ▁enfor ced ▁in ▁court . ▁In ▁Hart ley ▁v ▁P ons on by ▁it ▁was ▁held ▁that ▁where ▁a ▁remaining ▁crew ▁were ▁required ▁to ▁do ▁something ▁extra , ▁beyond ▁the ▁scope ▁of ▁their ▁contract s ▁( which ▁unlike ▁in ▁St il k ▁did ▁not ▁require ▁performance ▁in ▁all ▁emer gen cies ) ▁that ▁the ▁promise ▁of ▁extra ▁pay ▁could ▁be ▁enfor ced . ▁Another ▁exception ▁to ▁the ▁rule ▁that ▁performing ▁a ▁pre - ex isting ▁contract ual ▁duty ▁is ▁not ▁valid ▁consideration ▁for ▁a ▁new ▁agreement ▁was ▁created ▁in ▁Williams ▁v ▁Ro ff ey ▁B ros ▁& ▁Nich oll s ▁( Contract ors ) ▁Ltd ▁[ 1 9 9 1 ] ▁ 1 ▁Q B ▁ 1 ▁which ▁decided ▁that ▁in ▁such ▁situations ▁the ▁court ▁will ▁be ▁quick ▁to ▁find ▁consideration , ▁if ▁" p ract ical ▁benefits " ▁are ▁given ▁from ▁one ▁to ▁another ▁party . ▁The ▁practical ▁benefit ▁doctrine ▁has ▁recently ▁been ▁extended ▁to ▁a ▁le ase ▁agreement ▁which ▁involved ▁the ▁p ayer ▁of ▁a ▁less er ▁sum ▁in ▁M W B ▁v ▁Rock ▁Ad vert ising ▁[ 2 0 1 6 ] ▁E W CA ▁C iv ▁ 5 5 3 ▁which ▁has ▁led ▁to ▁considerable ▁criticism . ▁ ▁See ▁also ▁English ▁contract ▁law ▁Un iform ▁Com mer cial ▁Code ▁section ▁ 2 - 2 0 9 ( 1 ) ▁ ▁References ▁ ▁Bibli ography ▁Books ▁ ▁Articles ▁P ▁Luther , ▁‘ C amp bell , ▁Esp in asse ▁and ▁the ▁S ail ors