A Dungeons & Dragons riddle is:
 
Q: How do you ask out a D&D player?
A: Ask them for a D8 (date).
   
The joke has been cited in print since at least 2016 and has been printed on several images.
   
     
Wikipedia: Dungeons & Dragons
Dungeons & Dragons (commonly abbreviated as D&D or DnD) is a fantasy tabletop role-playing game (RPG) originally designed by Gary Gygax and Dave Arneson. It was first published in 1974 by Tactical Studies Rules, Inc. (TSR).  The game has been published by Wizards of the Coast (now a subsidiary of Hasbro) since 1997. It was derived from miniature wargames, with a variation of the 1971 game Chainmail serving as the initial rule system. D&D’s publication is commonly recognized as the beginning of modern role-playing games and the role-playing game industry.
     
Twitter
tyler @ beslubbering motley-minded jack-a-nape
@tyleranitar
How to ask someone to go to d&d with you: “Hey need a D8 tonight?”
9:07 PM · Sep 5, 2016·Twitter for Android
 
Twitter
lytelovespie
@1Dumagpi
@Yokal5
How do you ask a girl who plays D&D out?
Roll for a D8.
8:53 AM · Sep 6, 2016·Twitter Web Client
   
Twitter
Chris
@SoManyLimes
You want to ask the girl in your D&D group out? Simple, just ask her for a d8
8:33 PM · Sep 9, 2016·Twitter for Android
   
Twitter
Matafer
@_Matafer
How do you get a D&D player to go out with you?
You ask them a d8! #dndjokes #DnD #dadjokes
12:44 PM · Nov 10, 2016·Twitter for Android
   
Twitter
Nandiara Mystwalker
@Nandiara_RD
#Critters #Criticalrole How do you get D&D players to go out with you? Ask them for a d8!
1:42 PM · Nov 12, 2016·Twitter Web Client
   
Twitter
bloodbathory
@HouseBathory
How do you get a D&D player to go out with you?......
You ask them for a D8! 
@toddef didn’t laugh…
6:42 PM · Nov 12, 2016·Twitter for iPhone
   
Twitter
Stjep || Warlock in training
@StjepanLukac
How do you get a D&D player to go out with you?
You ask them for a d8.
#dnd #dungeonsanddragons #tabletop #lamepun
8:21 AM · Nov 30, 2016 from Wil (SG), Switzerland·Twitter for iPhone
 
Twitter
ook van librarian
@OOK_Librarian
How do you get a D&D player to go out with you?
You ask them for a d8.
4:43 PM · Jul 2, 2017·Twitter for Android
 
Twitter
Dragon Hearts Guild
@DH_Guild
Its time for today’s #dndjokeoftheday How do you get a D&D player to go out with you?
You ask them for a d8!!!
                                      #Dnd #pathfinder #5e #joke #JokeOfTheDay #funny #lol #dungeonsanddragons #dice #date #DatingTips #DatingAdvice
1:42 PM · Nov 17, 2017·Twitter for iPhone
 
Twitter
Renna Mira
@RennaCosplay
How do you ask out a D&D player?
Ask them for a D8
1:36 AM · Feb 18, 2019·Twitter for iPhone
     
Twitter
Renna Mira
@RennaCosplay
How do you ask the D&D player for a d8?
You DM them.
10:24 AM · Feb 19, 2019·Twitter Web Client
   
Reddit—DMDadJokes
Posted by u/Noobmaister69 January 2, 2020
How do you get a D&D player to go out with you?
Ask them for a d8!
 
Reddit—3amjokes
Posted by u/oxfordthethird Marc 1, 2020
How do you ask out a D & D player?
Ask them for a D8