Cheng Family-Duggan Family War

The Cheng Family-Duggan Family War is a large war that occurs during the events of GTA Online: The Diamond Casino & Resort between the Cheng Family from Hong Kong, and the Duggan Crime Family led by Avery Duggan.

Before the war
Before the war, in 2019 the Cheng Family Holdings CEO, Mr. Cheng, puts his recently open The Diamond Casino & Resort under management of his nephew Tao Cheng, hoping to turn a profit and get back his investment over the past five years.

Despite bailing out the Cheng Family whilst the construction of the Casino was underway, once it's finished, Avery Duggan and his Family sees this as a waste of money seek to buy the casino and turn it into something more profitable. To achieve this, they first attempt to sabotage the casino, destroying its value which will then allow them to buy everything at rock bottom price.

Tao Cheng disappear right after meeting the GTA Online Protagonist who were made aware of the current situation of the casino and hired by Agatha Baker the General Manager of the casino to save him from The Lost MC.

Start of the war
Right after saving Tao Cheng from the Lost MC, Agatha ask the assistance of the GTA Online Protagonist to protect the casino from the Duggan Crime Family, Avery paid several Hillbillies to go to the casino to start fight against the security and causing a scene.

The Hillbillies paid by Avery Duggan got repelled, however one of them manage to steal the sport car and run over a group of bikers who just arrival at the casino, still they got repelled and the sport car return back to the Casino.

Soon after this incident, The Duggan Family finally agree to meet Tao Cheng accompanied by Agatha Baker, his Translator and the Protagonist's crew at the Marlowe Vineyards to discuss the buyout of the Casino, however the meeting goes wrong and Avery Duggan send his henchmen to kill them which trigger the war between them and the Chengs.

Middle of the war
After the shootout at the Marlowe Vineyards, Tao Cheng's uncle decide to go to war against the Duggan Crime Family, by hiring the Protagonist to destroy all of his assets in Los Santos which they manage to do so.

In retaliation Avery send a large amount of mercenaries at the casino to kill Tao and the Casino staff, but his nephew Thornton Duggan arrival at the casino to tell them that he still want to buy the casino but that he and his uncle has a falling out due to the latter's ruthelessness and to warn them about the impending assault on the casino by his uncle's mercenaries, the assault was brutal but got repelled by the security and the Protagonist, after the assault Tao will speak to his uncle about what to do next.

Killing Avery Duggan
After the assault on the casino, Tao's uncle tell them to sell the casino as there's too much "drama" surrounding it because Tao's uncle provided much funding to renovate the casino, neither Baker and Tao can refuse him, as everyone prepare to move their belonging, Thornton arrival at the casino again and make an offer to everyone, he propose to save the casino by buying it from the Cheng Family at full price which will result as a transfer of ownership, however he admit that he won't have this much money until someone kill his uncle which will result Thornton to receive his full inheritance.

After informing by Thornton about his uncle's location, everyone turn their attention to the protagonist for help with a lot of money which they accepted.

They go to Martin Madrazo's house La Fuenta Blanca, rented by Avery Duggan, and kill all of his bodyguards and mercenaries if they were spotted, which led to Avery to escape by extrac helicopter, his last attempt to escape ultimately failed as he was killed by the GTA Online Protagonist, handing victory to the Diamond Casino staff and saving the Diamond Casino & Resort from the threat of the Duggan Crime Family.

Events of GTA Online: The Diamond Casino Heist
A few months after Tao Cheng is forced to sell The Diamond Casino & Resort to the Duggan Crime Family and returns to Hong Kong in 2019, Georgina flies to Los Santos and arranges a meeting between herself, Lester Crest and the GTA Online Protagonist in Mirror Park by hacking their phones. She approaches them and persuades Lester into planning the Diamond Casino Heist as revenge against the Duggans for taking advantage of her brother.

Later on, she shows up at the arcade center purchased by the GTA Online Protagonist to hear Lester's plan, as well as proposing her own, although she eventually reveals that she wants to invite Lester to the Richman Hotel to "have some food and discuss it all". After the arcade center is up and running, Georgina shows up once more to hear Lester's plans and approaches to the heist, and she tells the crew she will be staying at the Richman Hotel until the heist is pulled off and they should contact her if they need anything. However, Georgina is called back home on the day the heist is executed and therefore misses the action, but she returns to Los Santos just in time to personally thank the crew for successfully pulling off the heist.

It is later revealed that Georgina remains in contact with Lester after the heist and they kept the promise of robbing the Diamond Casino every week, allowing the protagonist to replay the heist whenever they receive a text message from Lester.

Factions
Two factions play a major roles in the war during the events of GTA Online: The Diamond Casino & Resort while others play a significant supportive roles.

The two factions who has a major role are: There's also other factions who appear in the war where they are either paid by the Duggan Crime Family or have no connection to them, those factions are:
 * The Diamond Casino & Resort staff represented by Tao Cheng (with the Casino Staff & Security, Tao Cheng's Translator, Agatha Baker, Brucie Kibbutz and the GTA Online Protagonist)
 * Duggan Crime Family led by Avery Duggan (with The Professionals crime syndicate)
 * The Hillbillies paid by the Duggans to cause trouble to the Casino.
 * The Lost MC who once kidnapped Tao Cheng.