Preliminary rounds will be held in 8 US cities, New York, San Francisco, Chicago, LA, Minneapolis, Dallas, Seattle, and Miami. And the finals will be held in NYC on October 7th 2017.
There are two age brackets, those older than 12 and those 12 and younger. And the qualifiers will be one specific level in Mario Kart 7, GBA Castle for older crowd and Luigi Mansion for younger. Lowest times in time trial advance to the finals but no word on how many advance from each city.
Nintendo hosted a Nintendo World Championships in 2015 and the original in 1990....and other similar events like PowerFest in 1994 and Nintendo Campus Challenge in 1991 and 1992.
All of the pre-2015 events have rare video games that came out of the competition. I'm keeping my fingers crossed that Nintendo releases some NWC 2017 disc that the winners get. It would be fun to have a new, limited edition collectible from Nintendo World Championships.
Good luck to all those who compete.