When timid bank clerk Stanley Ipkiss discovers a magical mask containing the spirit of the Norse god Loki, his entire life changes. While wearing the mask, Ipkiss becomes a supernatural playboy exuding charm and confidence which allows him to catch the eye of local nightclub singer Tina Carlyle. Unfortunately, under the mask's influence, Ipkiss also robs a bank, which angers junior crime lord Dorian Tyrell, whose goons get blamed for the heist.

Rhode Island State Trooper Charlie Baileygates has a multiple personality disorder. One personality is crazy and aggressive, while the other is more friendly and laid back. Both of these personalities fall in love with the same woman named Irene after Charlie loses his medication.