Sadri (defendant), a California resident, incurred a large gambling debt at a casino in Nevada. In exchange for two personal checks and two memoranda of indebtedness for the amount of the gambling debt, the casino gave Sadri additional chips, which Sadri lost while gambling at the casino. Sadri then stopped payment on the checks and memoranda. The casino assigned any claims it had on the checks and memoranda to Metropolitan Creditors Service (MCS) (plaintiff). MCS sued Sadri in California to collect the gambling debt. The municipal court entered judgment for Sadri, finding that, although Nevada law allows a cause of action for enforcement of gambling debts, judicial enforcement of Sadri’s gambling debts was against public policy in California, and the checks and memoranda were therefore unenforceable. The appellate court affirmed, and MCS appealed.