The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
Wikipedia[3][5][6] lists 20 November 2012; Steam shows 19 Nov 2012 (Pacific time); the Guardian's[2] 15 November 2012 preview (opened) contains the date.
Guardian preview of 15 November 2012 containing the 20 November 2012 release date.[1]
Series article listing the entry in the franchise's release order.[1]
Steam store page for the PC release; lists a Steam release date of Nov 19, 2012.[1]
Developer or studio page.[1]
Something missing or wrong? Say it in your own words: a link that backs this pin up, a different start or end date and why, or a fact it lacks or gets wrong. The AI checks it against this pin's sources, searches for better ones, and adds any page that backs you up. The pin's own sources still count most. A picture that shows something else, or shows it badly, is looked at too, and moved down or replaced.