If we take Horace Slughorn's description of Felix Felicis at face value and not just as a potion with some placebo effect, then in the case of Harry using it, it caused:
Horace Slughorn to get drunk and to share information that he otherwise would've preferred to withhold,
Harry to get lucky with his romantic interest, Ginny, after breaking her up with her boyfriend.
Does this mean that it can be used to 'get lucky' for getting a one night stand just as easily, making it the perfect rape drug? The preparator doesn't even need to strain himself trying to slip it to the victim and risk getting caught as the person can take it beforehand in the seclusion of his/her room.