Party

"The Party" was a close-knit group formed by the four boys Mike Wheeler, Will Byers, Lucas Sinclair and Dustin Henderson, which would later include Eleven, Stephanie Mayfield and Max Mayfield. 
The term "Party" originally referred to the four boys's 'Dungeons & Dragons' campaigns. After Will disappeared in 1983, the Party became instrumental in reacting to the odd phenomena occurring in their hometown. The Party typically used 'D&D' terminology as a means to explain and understand the supernatural phenomena they encounter.
In November 1983, Mike, Dustin and Lucas accidentally crossed paths with Eleven while investigating Will's disappearance. Within a short time, they befriended her and accepted her into the party. Later, in 1984, Max Mayfield and her sister Stephanie joined the party, and the older teens like Steve Harrington, Nancy Wheeler, and Jonathan Byers became important allies to them.
Some members of the Party were also associated with the Hawkins Middle School AV Club, and later, the Hellfire Club at Hawkins High.