I think this will work for your scenario: declare Interface end declare ConcreteType1 extends Interface end declare ConcreteType2 extends Interface end rule "asdf" when OtherType( $member : member ) ( $type : ConcreteType1(this == $member) or $type : ConcreteType2(this == $member) ) then // do whatever with $member end -- View this message in context: http://drools.46999.n3.nabble.com/Alternative-to-instanceof-when-matching... Sent from the Drools: User forum mailing list archive at Nabble.com.