793.9 that magical number that ought to be the PIN number or four digit code of all gamers of a certain generation.
793.9 the most important bit of any school library or the adult section of the public library when you were too young to afford any gaming books except at Christmas or Birthday.
793.9 the public secret code to the portal of gaming. The cupboard to Narnia of toy soldier gaming. As I recall in one lovely tiny branch library of my childhood, 793.9 was round the back of shelving and out of view from the rest of the library.
What was 793.9 in the mysterious world of Dewey library numbers?
793 Indoor games & amusements
793.2 Parties and entertainment
793.3 Social, folk, national dancing
793.4 Games of action
793.5 Forfeit and trick games
793.7 Games not characterized by action
793.8 Magic and related activities
793.9 Other indoor diversions
http://bpeck.com/references/ddc/ddc_mine700.htm
793.9 other indoor diversions including Wargames
793.9 has even generated its own 2014 book Dragons in the Stacks, as befits some of the more forward thinking libraries such as Kaptain Kobold’s local Australian library’s games events. http://hordesofthethings.blogspot.co.uk/2017/11/dragon-rampant-at-library.html
Mainly focussed on RPG games, snippets can be read on Google books.
http://www.librarything.com/mds/793.92 suggests that Wargames now have their own unique number 793.92
So who was Dewey the decimal library wizard? https://en.m.wikipedia.org/wiki/Dewey_Decimal_Classification
Here is the man himself, American librarian Melvil Dewey (1851-1931)

Would Melvil Dewey have approved of the activities categorised under 793.9?
Probably not, accorading to Anna Elliott’s article below. He did not seem too fond of “silly games” although arguably everything I have learned about history, psychology and tactics through gaming would class it as the sort of “self improvement activity” he enjoyed in place of “silly games” as a child.
http://www.hwwilson.com/databases/PDFsample/WLB/dewey.pdf
What a singular man Melvil Dui turned out to be …
Blogposted by Mark, Man of TIN, player of Games not characterized by action