▁is ▁usually ▁the ▁maximum ▁strength ▁of ▁most ▁Mon ster ▁cards ' ▁attacks . ▁Therefore , ▁player ▁can ▁only ▁damage ▁the ▁oppon ent ▁if ▁the ▁strength ▁of ▁an ▁attack ▁is ▁ 3 ▁or ▁higher , ▁and ▁the ▁damage ▁would ▁then ▁be ▁reduced ▁by ▁ 2 . ▁ ▁Despite ▁the ▁fact ▁that ▁most ▁Mon sters ▁are ▁unable ▁to ▁damage ▁the ▁Master ▁initially , ▁there ▁are ▁several ▁ways ▁to ▁increase ▁its ▁strength ▁so ▁that ▁it ▁can . ▁One ▁way ▁is ▁to ▁have ▁the ▁Mon ster ▁card ▁not ▁move ▁for ▁one ▁turn . ▁On ▁the ▁next ▁turn , ▁it ▁will ▁become ▁charged . ▁This ▁causes ▁the ▁strength ▁of ▁the ▁Mon ster ' s ▁charge ▁attack ▁to ▁increase ▁by ▁ 1 . ▁Player ▁also ▁can ▁use ▁items ▁on ▁the ▁Mon ster , ▁such ▁as ▁Power - up . ▁The ▁probably ▁most ▁preferred ▁way ▁to ▁strength en ▁a ▁Mon ster ▁is ▁by ▁increasing ▁its ▁level , ▁which ▁can ▁be ▁done ▁by ▁defe ating ▁another ▁Mon ster . ▁ ▁There ▁are ▁three ▁different ▁rule ▁sets ▁in ▁this ▁game : ▁Junior , ▁Senior , ▁and ▁Pro , ▁which ▁affect ▁the ▁number ▁of ▁cards ▁in ▁the ▁player ' s ▁deck ▁and ▁the ▁master ▁cards . ▁The ▁Junior ▁game ▁is ▁very ▁basic ; ▁players ▁use ▁de cks ▁of ▁ 2 0 ▁cards ▁( 1 5 ▁in ▁the ▁Game ▁Boy ▁Color ▁game ) ▁and ▁normal ▁Masters ▁with ▁ 5 HP . ▁The ▁Senior ▁game ▁is ▁basically ▁the ▁same , ▁but ▁with ▁the ▁addition ▁of ▁Magic ▁Master ▁cards . ▁The ▁Pro ▁rule ▁set ▁uses ▁