Friendship and love are important on this show, which often examines the ties that bind its five main characters to each other -- and to others as well. Two are married to each other, and their solid relationship is strong enough to weather the bumps of sitcom plot twists. Other characters bounce between periods of being in relationships and being single, and they turn to their friends to help them recover from the inevitable bruises of their up-and-down romantic lives.
Occasional comic pratfalls, etc. A running joke involves characters slapping each other.
Lots of innuendo and references to/discussions about sex, especially between amorous Marshall and Lily. Some fooling around on screen, and lots more is implied off screen. Characters are shown in various stages of partial dress, but there's no actual nudity. Barney is a serial womanizer who lives for casual hookups and avoids commitment.
Language includes "damn," "bitch," "hell," "ass," "bastard," "bang," etc.
Syndicated versions of the show's episodes sometimes include retroactive product placement (background TV screens showing clips from upcoming movies, etc.).
Drinking, Drugs & Smoking
The main characters frequently convene for drinks at a neighborhood bar. Some references to being drunk and making poor decisions while intoxicated.