I believe the answer is that Drools implements sub-rule compilation for rules containing "or". So in essence your rulebase contains the following once compiled:- rule "fire_twice_a" no-loop true when eval(true) then System.out.println("word"); end rule "fire_twice_b" no-loop true when eval(true) then System.out.println("word"); end -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of sergey.olifirenko Sent: 08 June 2009 13:39 To: rules-users(a)lists.jboss.org Subject: Re: [rules-users] OR operator affects how many times Rule's actionis executed More simple example: package continuated_rules dialect "mvel" rule "fire_twice" no-loop true when eval(true) or eval(true) then System.out.println("word"); end output is: word word why does it happens ? -- View this message in context: http://www.nabble.com/OR-operator-affects-how-many-times-Rule%27s-action -is-executed-tp23910106p23923259.html<http://www.nabble.com/OR-operator-affects-how-many-times-Rule%27s-action%0A-is-executed-tp23910106p23923259.html> Sent from the drools - user mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users