RNA-dependent RNA polymerase which replicates the viral genome. Catalyzes the transcription of fully conservative plus-strand genomic RNAs that are extruded from the virion into the cytoplasm where they function as mRNAs for translation of viral proteins and also as substrates for encapsidation to form new virions. Once encapsidated, the positive strand is converted to dsRNA by the RNA-directed RNA polymerase (By similarity). a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate + RNA(n+1) One molecule or two of Gag capsid protein is replaced in the virion by Gag-Pol because the fusion protein is essential for RNA encapsidation and replication. Produced by -1 ribosomal frameshifting. Belongs to the totiviridae RNA-directed RNA polymerase family.