Napoleon's characteristic card game? (4)
I believe the answer is:
solo
'card game?' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for solo that I've seen before include "Type of whist" , "Done by one person" , "On one's own, unaccompanied" , "Han - (Star Wars); fly unaccompanied" , "Unaccompanied passage" .)