Straddled along the The Strip between The Clown's Pocket and Royal Casino, Caligula's Palace is a Roman-themed casino hotel which, according to the game manual, is the largest hotel in the world. According to the GTA website, it was founded in 1972 (though not in its current form) and has always been mafia-controlled.
The casino is only one of three in the city (alongside The Four Dragons and an unnamed small-time "Casino") with an accessible interior, granting the player access to blackjack, roulette, video poker, and slot machines, and boasting the largest casino floor of the three accessible casinos. True to its theme, the casino is designed inside and out with lavish faux-Roman architecture, and the female bartenders are dressed in toga-like costumes. In addition to the usual casino patrons, the casino floor is also populated with patrolling security personnel who will response hostilely to the player if the player chooses to act violently (i.e. firing a gun or attacking people) within the casino floor.
The interior of Caligula's Palace also features a basement area, accessible via the Bank & Change counter, that houses managerial rooms, storage facilities, a loading area, and a high-security vault for the casino's finances. The player can also access the rooftop of the casino's tallest block via an elevator access from the casino floor, which leads player to the uppermost hotel suite corridor leading to two rooftop access points. Another elevated access that leads to the hotel's managerial suites is inaccessible barred during mission cutscenes.
The casino can be accessed as soon as the player unlocks the Tierra Robada/Bone County/Las Venturas landmass, and is accessible from that point on, regardless of events in the storyline. The casino serves as the starting place for a chain of missions from Ken Rosenberg and Salvatore Leone.
In the beginning of GTA San Andreas' storyline, the casino, as of 1992, is co-owned by three major mafia families: The Leones, the Sindaccos, and the Forellis, who assign Ken Rosenberg, by then a former partner of rouge Forelli goon Tommy Vercetti, to run the casino's day-to-day operations as a neutral party.
Over the course of the storyline, however, Leone head Salvatore Leone, with help from Carl Johnson, temporarily tightens the Leones' grip of the casino by weakening his rival's influence in the city, only to abandon the casino after it was robbed in an elaborate heist executed by Carl himself with help from a myriad of specialists and the Triads. The power vacuum created from the Leone's retreat from Las Venturas allowed the Sindaccos to move in on the casino and maintain control of it as late as events in Grand Theft Auto: Liberty City Stories (circa 1998).
Caligula's Palace is physically, for the most part, based on the real Las Vegas casino Caesars Palace. Certain details are taken from other casinos, like the waterworks from the Bellagio (both being Italy-inspired, although Bellagio was not built until 1998 and Caesars Palace has an impressive water show of its own) or luminant green windows from the MGM Grand. MGM Grand was also once the world's largest hotel, when it first opened in 1993.
As for its mafia management, the mafia had been mostly ran out of Las Vegas in the 1980s by the FBI, but the scenario might be based on a rumor that current casino billionaire Steve Wynn may have been connected with the Genovese crime family around 1985, all the way up to then-don Anthony "Fat Tony" Salerno. The decision by the three Liberty City Families to have Ken Rosenberg operate the casino is also likely to be based on Frank Rosenthal's role running multiple Las Vegas casinos on behalf of the Chicago Outfit during the 1960s and 1970s; Rosenthal and, presumably, Rosenberg are Jewish Americans.
- Caligula was a famous Roman Emperor who is popularly known for his tyranny, extravagance, and sexual perversion later during his rule, reflecting the corrupt origins of the casino. Having been assassinated, Caligula's demise mirrors that of Julius Caesar, which the real-life Caesars Palace is named after.
An overhead wireframe render of the casino's interior in GTA San Andreas, which can be found at the Las Venturas City Planning Department.