I've seen this only in one scenario, 4 players on 2 teams are choosing which type of car they will use, and when both players on the same team choose the same car, player 1 says to player 2, 'Stop duping me!' or 'Don't dupe me'. The only source I can find to back up this usage is Dictionary.com, which presents no source or examples, but cites a Random House dictionary. Any thoughts?
The Oxford Dictionary acknowledges dupe as an abbreviation of duplicate:
verb & noun
Short for duplicate, especially in photography.
[AS VERB]: how to dupe 35 mm slides on to 35 mm film
[AS NOUN]: black-and-white dupes
The application of dupe seems to be expanding beyond photography.