▁a ▁modified ▁version ▁of ▁international ▁rugby ▁league ▁rules ▁for ▁their ▁own ▁domestic ▁compet itions ; ▁as ▁a ▁result ▁the ▁rules ▁of ▁rugby ▁league ▁se vens ▁can ▁vary ▁too , ▁even ▁before ▁changes ▁implemented ▁by ▁competition ▁organis ers . ▁ ▁Match es ▁have ▁two ▁hal ves ▁of ▁seven ▁minutes . ▁Un limited ▁substitution s ▁are ▁allowed ▁from ▁a ▁squad ▁tot alling ▁ 1 2 ▁players . ▁In ▁se vens , ▁smaller ▁sc rum s , ▁formed ▁from ▁the ▁three ▁for wards ▁on ▁each ▁team , ▁are ▁formed . ▁All ▁k icks ▁for ▁goal ▁should ▁be ▁drop ▁k icks ▁in ▁se vens . ▁After ▁points ▁have ▁been ▁scored ▁a ▁tap ▁kick ▁restart ▁is ▁taken ▁by ▁the ▁non - sc oring ▁side . ▁ ▁The ▁World ▁Se vens , ▁the ▁world ' s ▁premier ▁se vens ▁event ▁while ▁it ▁operated , ▁had ▁two ▁ 7 ▁minute ▁hal ves ▁up ▁to ▁and ▁including ▁the ▁semi - final s ▁with ▁extra ▁time ▁played ▁in ▁the ▁event ▁of ▁tie ▁at ▁the ▁end ▁normal ▁time . ▁ ▁The ▁final ▁was ▁longer ▁with ▁two ▁ 1 0 - min ute ▁hal ves . ▁In ▁ 2 0 0 4 , ▁the ▁World ▁Se vens ▁tack le ▁limit ▁was ▁reduced ▁from ▁ 6 ▁to ▁ 4 . ▁ ▁Major ▁se vens ▁festiv als ▁ ▁World ▁Se vens ▁is ▁currently ▁susp ended ▁but ▁in ▁ 2 0 0 8 ▁it ▁emer ged ▁that ▁the ▁World ▁Se vens ▁could ▁make ▁a ▁com eb ack ▁by ▁ 2 0 1 0 . ▁ ▁A ctor