<Tr> <Td> 2011 </Td> </Tr> <Tr> <Td> 2012 </Td> <Td> Cold Stream DLC </Td> </Tr> <Ul> <Li> Left 4 Dead: Was released in November 2008 . The first game's development was started by Turtle Rock Studios, who were bought by Valve during the game's creation, with continued development occurring at Valve's studios . </Li> <Li> Left 4 Dead 2: Was released a year later in November 2009 . Valve attributed the short turnaround between the titles as a result of having many ideas to expand on the first game, but more than could be reasonably done through software patching or downloadable content . The fast turnaround of the sequel was initially criticized by many players of the first game, leading to a temporary effort to boycott the second game . Valve helped to placate matters, demonstrating that it was still developing content for the first game, including a crossover campaign, "The Passing", between the characters of both games . </Li> </Ul> <Li> Left 4 Dead: Was released in November 2008 . The first game's development was started by Turtle Rock Studios, who were bought by Valve during the game's creation, with continued development occurring at Valve's studios . </Li>

How many left 4 dead games are there
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