By default, the generated JAR file is included in the RAR file. This behavior is controlled by the includeJar property. For instance, to exclude the generated JAR file from the RAR, set the includeJar property to false.
[...] <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-rar-plugin</artifactId> <version>2.4</version> <configuration> <includeJar>false</includeJar> </configuration> </plugin> </plugins> </build> [...]
Then execute the plugin by invoking the rar:rar goal.