Fraudulent: means fake, usually criminal, usually used for things not people e.g. 'She used a fraudulent credit card.' 'He has a fraudulent passport.' Deceitful: used only for people, means they try to confuse/mislead others for their own good e.g. 'The deceitiful person used a fraudulent credit card.' This is always used negatively, i.e. A magician (for example) is not deceitful. Deceptive: this refers to the effect something has on the speaker. If something is deceptive, it has misled the speaker/caused them to believe something which is not true e.g. 'This lake is deceptive. It looks shallow, but it's actually very deep.' Deceptive does not necessarily have a criminal/negative meaning.