These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
This page covers the franchise as a whole. If you're looking for the original BioShock game, see: YMMV.Bio Shock 1.
Anvilicious: The series isn't subtle in its imagery, which unfortunately means that the messages that are subtle are easily overwhelmed. Extremism in any human endeavour is bad; this is more or less the true message of the games, represented with all of the major villains and settings. Any time you encounter an individual who pursues something to an extreme, it all ends poorly.
Drugs Are Bad: Rapture is full of addicts. ADAM isn't technically crack, but it sure is desirable.
Love to Hate: There are many despicable characters in the franchise, from Andrew Ryan to Sofia Lamb to Sander Cohen to Zachary Comstock to Jeremiah Fink — and that's not even mentioning the undisputed heavyweight champion of evil BioShock villains, Frank Fontaine. But damn if they don't tend to be great orators.