No story can be a great love story unless there's some conflict. Two people who meet, fall in love and live happily ever after without ever even arguing whose turn it is to do the dishes is just too boring.
Much of Rick and Ilsa's romance is unseen, as it takes place long before the events of the film. Most of what is splashed on screen is the two coping with various perceived injustices that have been committed for the sake of their relationship. It's a glorious train wreck at times, and then we even get to see the train hop back up on the track.
But it's not just the love story where lies and deceit run amok. Rick has to deceive Renault to help get Victor and Ilsa out of town; Ilsa has deceived her husband about her past. Renault deceives Rick when he calls Strasser, and Rick deceives just about everyone when he hides those letters of transit. These people's actions may not scream "transparency," but we can totally see through it.
Questions About Lies and Deceit
If Ilsa really thought Victor died in a concentration camp, why didn't she tell Rick about him back in Paris? What did she have to hide?
Why didn't Ilsa ever tell Victor about her fling with Rick? Since he's a loving, understanding husband, shouldn't she have trusted him to be chill about it?
Some characters in Casablanca deceive others, but not necessarily with cruel intentions. Are there times when lying to or deceiving someone else is actually the right thing to do?
Renault is basically the poster child for two-facedness and deceit. Was saving Rick at the end really an unselfish action, or could he have had some ulterior motive?
Chew on This
Ferrari claims he's a baddie, but based on what we see in the film, he's actually one of the most honest characters around.
Rick is technically being dishonest when he rigs the roulette wheel in Jan and Annina's favor, but because it's well intentioned, it can't really be categorized as "deceitful."