<P> Arrow follows billionaire playboy Oliver Queen (Stephen Amell), who, after five years of being stranded on a hostile island, returns home to his mother, Moira Queen (Susanna Thompson) and sister, Thea Queen (Willa Holland) and becomes a bow and arrow - wielding vigilante . He is initially aided by his friends, John Diggle (David Ramsey) and Felicity Smoak (Emily Bett Rickards), and later aspiring vigilantes Roy Harper (Colton Haynes), Ray Palmer (Brandon Routh), Curtis Holt (Echo Kellum), Rene Ramirez (Rick Gonzalez), Evelyn Sharp (Madison McLaughlin), Rory Regan (Joe Dinicol), and Dinah Drake (Juliana Harkavy) join them . In addition, Queen's team receives help from the Lance family; Laurel (Katie Cassidy), Sara (Caity Lotz), and Quentin (Paul Blackthorne), sharing the goal of bringing justice to Starling City (later Star City). The series also featured flashbacks in most episodes in the first five seasons to the time Queen was missing, and how his experiences there shaped him into the man who returned home to fight crime . </P> <P> As of May 17, 2018, 138 episodes of Arrow have aired, concluding the sixth season . On April 2, 2018, the CW renewed the series for a seventh season . </P> <Table> <Tr> <Th_colspan="2"> Season </Th> <Th_colspan="2"> Episodes </Th> <Th_colspan="2"> Originally aired </Th> <Th_colspan="2"> Nielsen ratings </Th> </Tr> <Tr> <Th> First aired </Th> <Th> Last aired </Th> <Th> Rank </Th> <Th> Average viewers (in millions) </Th> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 23 </Td> <Td_colspan="1"> October 10, 2012 (2012 - 10 - 10) </Td> <Td> May 15, 2013 (2013 - 05 - 15) </Td> <Td> 130 </Td> <Td> 3.68 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 23 </Td> <Td_colspan="1"> October 9, 2013 (2013 - 10 - 09) </Td> <Td> May 14, 2014 (2014 - 05 - 14) </Td> <Td> 128 </Td> <Td> 3.28 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 23 </Td> <Td_colspan="1"> October 8, 2014 (2014 - 10 - 08) </Td> <Td> May 13, 2015 (2015 - 05 - 13) </Td> <Td> 135 </Td> <Td> 3.52 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 23 </Td> <Td_colspan="1"> October 7, 2015 (2015 - 10 - 07) </Td> <Td> May 25, 2016 (2016 - 05 - 25) </Td> <Td> 145 </Td> <Td> 2.90 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> 5 </Td> <Td_colspan="2"> 23 </Td> <Td_colspan="1"> October 5, 2016 (2016 - 10 - 05) </Td> <Td> May 24, 2017 (2017 - 05 - 24) </Td> <Td> 147 </Td> <Td> 2.21 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> 6 </Td> <Td_colspan="2"> 23 </Td> <Td_colspan="1"> October 12, 2017 (2017 - 10 - 12) </Td> <Td> May 17, 2018 (2018 - 05 - 17) </Td> <Td> 181 </Td> <Td> 1.76 </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Season </Th> <Th_colspan="2"> Episodes </Th> <Th_colspan="2"> Originally aired </Th> <Th_colspan="2"> Nielsen ratings </Th> </Tr>

How many episodes in each season of arrow