Scam
A scam is an intentional deception to deprive another person of his or her right and to secure an unlawful gain and thus a dishonest scheme, resp. fraud;
A confidence trick is an attempt to defraud a person or group after first gaining their trust. Confidence tricks exploit victims using their credulity, naïveté, compassion, vanity, confidence, irresponsibility, and greed. Researchers have defined confidence tricks as "a distinctive species of fraudulent conduct [...] intending to further voluntary exchanges that are not mutually beneficial", as they "benefit con operators ('con men') at the expense of their victims (the 'marks')".