A “pot luck” or “potluck” dinner is one where each guest brings a dish. The dish usually does not contain “pot” (marijuana).
 
“They had a ‘pot luck’ dinner at my high school. The police had to come when the parents realized it wasn’t a marijuana lottery!” was posted on Twitter  on July 27, 2011. “There will be no marijuana served at this year’s Potluck Dinner. #churchbulletin” was posted on Twitter on December 6, 2012. “‘Pot Luck Dinner’ at work today. It took a lot of work to get all of that marijuana and a lotto ticket in each of those brownies” was posted on Twitter on December 15, 2012.
 
“Is it okay to bring marijuana brownies to Pot Luck dinner?” was posted on Reddit—Shower Thoughts on February 2, 2018.
 
   
Wikipedia: Potluck
A potluck is a gathering where each guest contributes a different and unique dish of food, often homemade, to be shared. Synonyms include: potluck dinner, spread, Jacob’s join, Jacob’s supper, faith supper, covered dish supper, dish party, bring and share, shared lunch, pitch-in, bring-a-plate, dish-to-pass, fuddle, and carry-in.
           
Twitter 
Jaco Scholtz.‏
@Jaco01Scholtz
They had a ” pot luck” dinner at my high school. The police had to come when the parents realized it wasn’t a marijuana lottery!
12:43 AM - 27 Jul 2011
   
Twitter
TedInJest‏
@TedInJest
There will be no marijuana served at this year’s Potluck Dinner. #churchbulletin
9:14 AM - 6 Dec 2012
 
Twitter   
Don Theo‏
@Dontheo3
“Pot Luck Dinner” at work today. It took a lot of work to get all of that marijuana and a lotto ticket in each of those brownies.
12:54 PM - 15 Dec 2012
 
Twitter 
Kelly Kirby‏
@Atlbeautyexpert
“Pot” luck party has a brand new meaning: Beverly Hills Cannabis Club’s Marijuana-Infused Dinner -... http://fb.me/1iLDfjsDS
10:15 AM - 27 Jul 2013
 
Twitter
Evan Bookbinder‏
@WxManBookie
“Pot Luck” dinner? Get it? #punny RT @fox4kc: Police: Teacher brought marijuana-laced food to after-work pot luck http://link.fox4kc.com/1hCbCAV
8:12 PM - 26 Jan 2014
 
Twitter
Mike Otis‏
@MikeorMrMike
Fox News tweeted “Pot luck dinner:” at beginning of tweet about marijuana bars growing trend at weddings—Brings new meaning to “Pot Luck”
11:19 AM - 30 Aug 2015
   
Twitter
azfl com‏
@azflcom
Holy Smokes! New meaning for potluck dinner @mercnews: 6 eat cookies at church, later test positive for marijuana http://bayareane.ws/1RNoB20
11:29 AM - 1 Jun 2016
 
Twitter
Alex Smith‏
@Gavcam83Alex
Put marijuana in the food because the memo said ‘Pot Luck’.
#OfficePartyDosAndDonts
12:15 PM - 17 Dec 2016
 
Twitter
Hambone‏
@TXoilCons
I was invited to something called a potluck dinner. Apparently they call their marijuana strain here “casserole”  #HuffPoInTheHeartland
4:50 PM - 13 Jul 2017
 
Reddit—Shower Thoughts
Is it okay to bring marijuana brownies to Pot Luck dinner?
submitted February 2, 2018 by phironuthi