Trick played by an NCO? (3)
I believe the answer is:
con
'trick' is the definition.
(a con is a fraud or trick)
'played by an nco?' is the wordplay.
'played by' is an anagram indicator (I've seen this in other clues).
'nco' anagrammed gives 'CON'.
(Other definitions for con that I've seen before include "Diddle" , "Rook" , "Swindle, deception" , "Swindle in draconian way" , "Prisoner (sl.)" .)