The movie was based on Nicholas Pileggi's book, "Casino," which tells the same story in real life. Only the names were changed in the film. "Ace Rothstein" is really Larry (Lefty) Rosenthal. "Nicky Santoro" is Anthony (The Ant) Spilotro, "a very scary guy," to cop a quote from Another Crime Movie. In fact, everyone in the film is based on real-life characters. Oscar Goodman, the guy who plays Ace's lawyer, was his and The Ant's lawyer in real life, and is now the mayor of Vegas.
I thought Sharon Stone gave a very intense performance, credible as someone who cannot overcome her compulsive use of drugs and attachment to her pimp lover (superbly played by the Sultan of Sleaze, James Woods). Seeing her being transformed from glamor girl to nutcase still scares me.