The event took place during Labor Day weekend on Saturday, September 1, 2018, at the Sears Centre Arena in the Chicago suburb of Hoffman Estates, Illinois.

The event aired live on traditional PPV outlets, FITE TV, and Honor Club, but it was later made available for on-demand viewing on the NJPW World streaming service.

On the undercard, Cody defeated Nick Aldis to win the NWA Worlds Heavyweight Championship, Jay Lethal successfully defended the ROH World Championship against Flip Gordon, and IWGP Heavyweight Champion Kenny Omega defeated Penta El Zero in a non-title match.

[15][16][17] On March 5, All In's venue was revealed as the Sears Centre Arena located in the Chicago suburb of Hoffman Estates, Illinois.

[18][19] Over the coming weeks, independent wrestlers would be announced to take part in the show, including Penta El Zero, Rey Fénix, Kazuchika Okada, Deonna Purrazzo (though she would later be removed after signing with WWE), Tessa Blanchard, Jay Lethal, Chelsea Green, Marty Scurll, and Hangman Page.

[20][21][22][23] Additionally, it was announced that to coincide with the event, Conrad Thompson would hold Starrcast,[24] a fan convention which would feature numerous wrestlers and wrestling and podcast personalities including Jeff Jarrett, Eric Bischoff, Bruce Prichard, Diamond Dallas Page, and Macaulay Culkin.

[25][26][27][28] During the All In press conference on May 13, it was announced that Rey Mysterio and NWA Worlds Heavyweight Champion Nick Aldis would be taking part in the event.

[31][32][33][34] During this time, Cody and The Young Bucks started a YouTube series called All Us, chronicling the lead-up to the event.

[38] On August 6, it was announced on Being The Elite that All In's main card would broadcast on pay-per-view and Fite TV,[39] with an hour-long pre-show called Zero Hour airing on WGN America at 6:00 p.m. Eastern time.

[39] Later that day, it was announced that the event's main card would also broadcast on ROH's streaming service Honor Club.

[40] Additionally on August 6, Jordynne Grace, Moose, Rocky Romero, Colt Cabana, and Ethan Page were announced for the show.

[49] Wrestler Adam Birch was scheduled to be a producer on the show, but in the early morning hours of September 1 he was arrested in Schaumburg, Illinois after police noticed him sleeping in his car and discovered he had an outstanding warrant in Florida.

[50] All In comprised eleven professional wrestling matches, including two on the Zero Hour pre-show, that involved different wrestlers from pre-existing scripted feuds and storylines.

On April 10, Joey Ryan was (kayfabe) killed on Being The Elite by a mystery assailant in a Japanese hotel room.

[54] On June 4 on Being The Elite, Japanese police arrested Arrow star Stephen Amell for Ryan's murder.

[49] On June 8 at a WrestlePro event, Madison Rayne and Maxwell Jacob Friedman defeated Brandi Rhodes and Flip Gordon to qualify for All In.

[31] On the August 7 episode of All Us, a four corners match between Rayne, Dr. Britt Baker, Chelsea Green and Tessa Blanchard was announced.

[76] On August 7, it was announced that Jay Lethal would defend the ROH World Championship against the winner of the over-budget battle royale.

[81][82] Cody and The Young Bucks appeared on stage to start the event, offering to the live audience free merchandise, which was distributed by staff from Hot Topic and Pro Wrestling Tees.

[81] Next, the Over Budget Battle Royale took place with 19 participants vying to face Jay Lethal for the ROH World Championship on the main card of All In.

[81] However, El Hijo De Chico returned and superkicked Ray, then unmasked himself revealing Flip Gordon.

[82][84] After this, Dr. Britt Baker, Chelsea Green, Madison Rayne and Tessa Blanchard faced off in a four corner survival match.

Next, Jay Lethal defended the ROH World Championship against the over budget battle royale winner Flip Gordon.

Upon closer examination, it was a second Penta El Zero, who unmasked to reveal himself as Chris Jericho, and challenged Omega to a match at his Rock 'N' Wrestling Rager at Sea cruise.

[86] John Moore of Pro Wrestling Dot Net recommended the event, but pointed that it "suffers [from] that ROH and New Japan problem of having too many matches".

[94] Writing for The Ringer, Mike Piellucci praised All In, calling it "one of the greatest wrestling shows in recent memory".

Despite the main event being significantly cut short due to time constraints, Meltzer gave that match a 4+1⁄2-star rating.

[99] On January 1, 2019, Cody and The Young Bucks founded their own promotion, All Elite Wrestling (AEW), with backing of billionaire businessmen and owners of the Jacksonville Jaguars and Fulham F.C., Shahid and Tony Khan, the latter becoming the President and chief executive officer of AEW, with Cody and The Young Bucks being executive vice presidents.

[102] During Double or Nothing on May 25, 2019, AEW announced that the Sears Centre would host All Out, the company's second pay-per-view event, on August 31, 2019, the day before the first anniversary of All In.

Ring of Honor retained the rights to the All In footage as a condition for Cody and The Young Bucks to promote the event.